Mr. Donnell Koh has been my civics tutor as well as my chemistry teacher at Raffles Junior College. He is one of the best teachers I have come across throughout my schooling years ... he cares for the well-being of all his students and exhibits care towards every individual in the class ... he commands a respect from his students ... his teaching is highly effective and his lessons are always well-taught and very comprehensible...his students almost never lose focus during lesson and always take away new knowledge after each lesson...the difficult concepts appear to be much easier when he explains...I will attribute my successful application to Cambridge University to Mr. Koh entirely. His strong recommendation and excellent teaching has been the reason why I am able to receive an offer from such a prestigious University."

Han Shuting, RJC 2005 - 2006
(Medicine - Cambridge)

"Mr Koh was a strong pillar on which the class dynamics was built upon. For instance, he would initiate class CIP and conduct interesting lessons (especially during civics lessons) to strengthen class bonds. I admire Mr Koh’s uncanny ability to strike a balance between his professional and brotherly demeanor such that he can be a supremely effective teacher and friend at the same time...it seems almost unfair that Mr Koh is armed with such a formidable arsenal of teaching techniques. He has the ability to slow down to make the weaker students understand, and also the ability to incessantly challenge and intrigue stronger students...It is excessively difficult to exaggerate Mr Koh’s qualities as a teacher – a mentor, as I would wish to, for the sake of writing an outlandish testimonial. Indeed, he epitomizes the spirit of a teacher so well that there is little room for that.

Kho Chen Han George, RJC 2005 - 2006

"I would describe Mr Koh as not only a knowledgeable teacher who is always ready to clear our doubts regarding our work, but also a dedicated friend whom we all respect...The learning environment was kept fun during chemistry tutorials...Being good- natured, he often encouraged us to be actively involved in community service and even joined us on our class CIP where we volunteered to do mural painting at the Institute of Mental Health. Mr Koh was supportive not only as a teacher but as a friend, often expressing concern over how we were coping with both studies and CCA, and offering advice on all our unduly worries of our future...It was a memorable time for me in Junior College, in a wonderful class with such an inspirational teacher to guide us along."

Lin Shumin, RJC 2005 - 2006

"Mr. Koh is easily one of the best Chemistry teachers in RJC, if not the best. He is able to articulate complex concepts to students in a manner that is easy to grasp and comprehend. In other words, he makes difficult concepts simpler to absorb. His tutoring skills have developed to a stage where he can predict most of the common mistake students often make when attempting questions. His lessons are not only engaging but also enriching. It is because of his tutoring that my Chemistry has improved tremendously, and I am very certain that he has worked wonders for many of my fellow schoolmates as well. Mr. Koh possesses all the characteristics of a model tutor. It is not an exaggeration to say that every student would like to have a tutor like him. He clearly has the passion and zest for teaching. Personally, he has inspired me to enjoy Chemistry, which is truly remarkable. All in all, he makes learning a rewarding experience."

Koh Kian Leon, RJC 2005 - 2006

"Mr. Koh has been a terrific chemistry tutor and role model for me. He is one of those rare teachers who can compound flippancy and conscientiousness, both an easy-going mate and a serious worker. In this he sets an endearing example of exemplary conduct and work ethic without the stifling nitpicking that sets student’s teeth on edge. His patience and concern with understanding of the subject establishes him as a top tier teacher who truly deserves the respect and affection my class and I give him."

Si Yuan Shen, RJC 2005

"Mr Donnell Koh is, first and foremost, a teacher who shows much dedication in his work. With much patience, he would go the extra mile to see that his students attain a better understanding of Chemistry, even if it means going through what he has already gone through before. Mr Koh's approachability endears him to his students. Adding in his sense of humour, what you have then, is a teacher to remember."

Matheus Yeo, RJC 2005 - 2006

Mr Koh saw me through A level chemistry at RJC and he is one of the most dedicated teachers i’ve known. He stresses on ‘getting the basic concepts /big picture’ because he believes that once we have the concepts at our finger tips, we will be able to tackle any exam question. Thereafter, he will expose us to a variety of questions and teach us strategies to approach the question in an exam smart manner.

Mr koh will not dismiss questions raised by his students as ‘irrelevant’ or ‘too silly’. Through these questions, he is quick to detect misunderstandings that the student may unknowingly have. Because of his approachability and patience, students dare to clarify doubts and hence gain a better understanding in the subject. I remembered how Mr Koh took a personal interest in every student’s progress. He ensures that no student is left behind by organizing small group tutorials to meet the needs of each student. Such a teacher who goes beyond his call of duty is hard to find these days.

Having him as my chemistry tutor is one of the greatest blessings in my JC days. I strongly recommend him to anyone who is struggling with basic chemistry and those seeking to understand higher level chemistry concepts!

Charlotte Tan, RJC 2005 - 2006
(Medicine - NUS)

Mr Koh had been a superb civics tutor when he was still teaching back at RJC. Despite having to handle a rather playful civics tutorial group, he was always patient with us, giving his best efforts both inside and outside of the classroom. Even after he left RJC, Mr Koh continued to show tons of care and concern for his students. He remembered birthdays, wished us luck for our exams and was extremely concerned with our academic progress.

As a private tutor, Mr Koh showed relentless commitment to teaching as well, preparing to-the-point summarised lecture notes and comprehensive practice questions for every single topic. Under his tutorage, I have made tremendous improvements in my grades. In addition, his humorous style of teaching completely transformed boring Chemistry lessons into interactive and engaging ones. Most importantly, he was always able to explain abstract Chemistry concepts in simple layman terms, ensuring that everyone in class understood fully. All in all, I strongly believe that he would continue to produce many more outstanding students.

Kehui, RJC 2007 - 2008

H2 Chemistry used to be the burden of my JC life. no matter how hard i tried to study, i just couldnt figure it out. and now, after attending just weekly lessons, my grade has improved drastically. More importantly, Mr Koh gives me the confidence that i need to ace my As! And i'm sure that applies to everyone who went for his lessons too. Probably the most fun and interesting tuition ever. Twig!!

Marcus Ng, RJC 2007 - 2008

I've always hated Chemistry until I went to Twig. Twig breaks down chem topics into easy-to-understand bits, which makes learning H2 Chemistry no longer boring and dry but interesting and interactive. If you are still struggling to comprehend those thick school notes with lots of unnecessary materials, hesitate no more. Going to Twig is one of the most useful decisions you can make to improve your Chemistry grade!

Zhuang Yi, RJC 2007 - 2008

Joining Twig Learning Center in early 2008 was one of the best academic decisions I have made. For most of my JC life, I was uninterested in Chemistry. It was a confusing subject quagmired in thick notes and my grades left much to be disired. Lessons with Mr Koh changed that - his lessons made each topic simple, direct and to-the-point. It gave me the firm foundation in Chemistry knowledge that I badly needed, and that gave me the confidence to handle the subject.

In addition, Mr Koh is also a very patient tutor. He ensures that have full understanding of the explanation to the many (many) questions that I asked, always explaining every answer from its very core concepts upwards to strengthen my foundation. This I found very helpful, as it taught me how to handle any questions in examinations. He goes the extra mile for his students, staying behind after each lesson (sometimes for many hours) so that we can clarify our doubts.

As a result of his efforts, not only have my Chemistry grades improved, I find Chemistry interesting (believe me, this is no mean feat). The one subject that I couldn't wait to get rid of in JC1 is presently one that I hope I will have further opportunities to study. Thank you Mr Koh.

Xue Wei, RJC 2007 - 2008

Mr Koh, you are a natural teacher. There are some people who are born to be writers, poets, artists, etc, and your gift is in teaching. One explanation is always enough. Twig's notes are short, clear and to the point, and it really prepares one well for examinations. On the contrary, school notes can be thick, confusing, and sometimes incomplete cos the lecturer swiches slides before we even finish copying!

The best part about Twig is that we're always free to ask you questions anytime during the lesson. The class is small, and even if we do not ask questions, we benefit listening to other students' questions and hearing the explanantion. It is impossible to ask so many questions in tutorials at school, and even more difficult to hear the questions my classmates ask because school tutorials are so noisy! At Twig, we never face this problem.

I joined Twig because my H2 Chemistry grade dropped from A/B in JC1 to a E in JC2 CT1, largely because organic chem was a new topic and I didnt understand it well initially. After I joined Twig, my grade improved from E to A within the span of 3 months, even topping the class! Even my school tutor could not understand how I managed to improve so much!

Twig's Chemistry lessons are the only lessons which I look forward to attending. Sometimes I dread going to school but I enjoy the cosy atmosphere at Twig!

Hu Ching, RJC 2007 - 2008
(PSC Scholar)

H2 Chemistry was never my best subject and I often took a long time to master each topic. Weekly tuition at Twig accelerated my conceptual understanding and enhanced my application skills greatly. Twig's notes are concise and encapsulate well the required definitions and qualitative explanations under the syllabus as well as provide sufficient basic and advanced level practices. More importantly, Mr Koh is a natural and extremely adept teacher - his explanations never failed to aid me in internalizing what I could not fully comprehend from lectures and tutorials in school. That is perhaps the greatest comparative advantage that Twig can offer over other tuition centres. Mr Koh makes a conscious effort to link new topics to old ones, building on past understandings to re-establish new ones. He uses as well simplified models and this diagramatic approach to teaching is truly effective in honing a holistic understanding. I am most grateful to Mr Koh for his willingness to clarify my queries in the month before the A level examinations. That I was able to process his explanations over email is but a testament to my strong foundation of the subject that he managed to build.

Thank you Mr Koh!

Ying Jie, RJC 2008 - 2009

Describing Donnell as an excellent teacher will definitely not be an overstatement. He is able to communicate very effectively with his students and seems to have a nack of making difficult concepts look easy. As a teacher, he is selfless in assisting students under his charge to achieve grades which may have been seemingly out of reach. He wouldn't hesitate to offer assistance to students in need and would have no qualms staying back an hour or more just to brush up chemistry concepts which they could not grasp during lesson time. Ample practice is definitely provided during lessons for students to put their problem solving skills to the test. All in all, TWIG has a wonderful package of lessons provided and with such a wonderful, caring and compassionate teacher at the helm, it is undoubtedly the place to be if you would like your H2 chemistry grades to improve by leaps and bounds.

Jonathan Sim, RJC 2007 - 2008 and
Deborah Sim, TJC 2008 - 2009

I never had a really keen interest in chemistry. But failing my first ever H2 chemistry test in JC caused me to actually want to go for tuition for the first time in my life, thus beginning my journey at Twig. After attending Twig, thanks to Mr Koh’s patient guidance, my H2 chemistry results improved tremendously, to the extent that I never got anything lower than a B for my school exams. Mr Koh’s concise and easy to understand notes also helped me develop a greater understanding for the various chemistry topics. Mr Koh conducts lessons in an interesting manner. He once demonstrated the electrolysis of sodium chloride for us in the classroom! His enthusiasm for chemistry also helped me develop a greater interest in chemistry. Mr Koh is always on hand to answer my queries and help me when I encounter any problems when doing the many practice questions he gives us. With Mr Koh’s guidance, I was one of the top students in my cohort for H2 chemistry during my prelim examinations, and eventually got an A in H2 chemistry for my A levels. Thank you Mr Koh!

Gwee Xin Yi
Hwa Chong Institution 2008 - 2009

Hi Mr Koh, I am very grateful to you for your guidance for the past two years. If it’s not for you, I doubt I would be able to achieve A for H2 Chemistry! Other than preparing notes on every topic, you would even point out the important sections that we ought to remember or be aware of, making our learning much easier, on top of having to study our school notes. Not to forget, you also provided us with many useful topical practices, as well as booklets with different topics for our revisions before prelims and A level. I especially love the experiments that you had performed in class! Just by using items that can be found around us in our daily life, you make lessons and chemistry more interesting! I doubt any other chemistry tutors do that during their lessons. You are also patient and clear in explaining concepts and queries whenever I go to lessons early or even after lessons when I stayed back for a while. Not only that, you also care a lot for your students, I still remembered that you sent me a sms to remind me to take good care of my eyes when I am unwell. I really appreciate your care and concern. I never regretted going to TWIG for tuition and meeting such a fun and nice teacher like you. Once again, a very BIG thank you! I bet now I will be able to start filling up the best-seller book written by you with more adventures! =) Once again, thank you very much!

Li Ting Jurong JC 2008 - 2009

Mr Koh is one of the best tutors that I have had. He has a natural ability to simplify abstract concepts through the use of examples and analogies, making H2 Chemistry simple and easy-to-understand. He is a patient and committed tutor who always ensures that every student has a clear understanding of the topic at hand. Mr Koh is able to integrate seemingly unrelated topics, building a better understanding of H2 Chemistry as an entire subject and preparing us for the (increasingly common) challenging cross-topic questions.

With his persistent guidance and the help of his concise and effective notes, I have never had to worry much about H2 Chemistry, leaving more time for me to focus on my poorer subjects. Mr Koh makes Chemistry an interesting and manageable subject. Thank you Mr Koh!

Qin Ying
Nanyang JC 2008 - 2009
(Scored A for 2009 A-Level Chemistry)

I never had much interest in Chemistry and it had been one of my weakest subjects since secondary school. However, after attending Mr Koh’s tuition classes in J2, it became a different story altogether! The simple experiments that he conducted in class, like for electrolysis, and the examples that he used to show how H2 Chemistry is involved in our everyday life made Chemistry become a life subject. Thus, it was not difficult to give him my 100% attention! His concise notes made it easier for me to revise and understand all the concepts that were required especially in application questions. Also, his patient guidance and constant encouragement helped to alleviate my fear in attempting difficult questions instead of avoiding them, like in the past. Thanks to Mr Koh, I achieved an A in my H2 Chemistry for A Levels! Thank you Mr Koh!!!

Shu Jun
Yishun JC 2008 - 2009

Thank you for teaching me H2 Chemistry! You made the subject simple and easy to handle. I've improved by 4 grades since you tutored me! I really enjoy your teaching and it is very effective. Most importantly, thank you for the continuous support you have shown, be it in the words of encouragement after I've SMSed you my results or the extra consultation lessons you're willing to offer. You are the best Chemistry tutor I've come across in all my years of education!!! Thank you very much Mr Koh! : )

Deborah Chua, RJC 2009 - 2010

Thank you Mr Koh for being a patient and dedicated teacher, for giving me that boost of confidence and wealth of knowledge. Honestly, I have never liked Chemistry in my entire life as a student.... until this year when you taught me just how fun Chemistry really is. Before you taught me, I would blindly memorise formulae and mechanisms. Howver, since you taught me what many of my school teachers would tell me to "just accept", I can truly understand and appreciate the Chemistry, which I believe is what a good education should really be. And I owe this all to you. Truly, you are the most patient and inspiring teacher I've ever come across. And I believe many other students feel the same too. = ) So thank you for being a teacher like you are and I hope you will continue doing what you do best and be a blessing to many others like myself!

Melissa, ACJC 2009 - 2010

Every lesson, Mr Koh's ultimate goal is to help students, like myself, understand chemistry better than before we enter his classroom. His notes and worksheets captures the essence of the topic and are carefully crafted so that it meets the requirements of school and the syllabus. His explanations are very clear and concise. With on-the-spot questions to try out, individual attention is given to everyone when we need help with solving them, so that we could work through the questions at our own comfortable pace. This is crucial given that every student has their own doubts and misconceptions.  Having some individual attention would effectively clear any doubts then and there. No doubt, he is always willing to help us with all our queries about the subject. Through his guidance, my understanding of chemistry has greatly improved! He is simply amazing at using simpler alternative ways to explain seemingly difficult concepts. I am very grateful to you for all the time and effort that you have put in to help me with chemistry. It is a great fortune to be able to attend your classes.  I strongly believe that you will continue to explore the potential of many other students in the future. A great big thank you to you, Mr Koh!

Joan, HCI 2009 - 2010

 
Mr Koh is an excellent Chemistry tutor - passionate, dedicated and well-organised! His lessons are always ever so dynamic and interesting, with loads of fun added into his lessons through on-the-spot experiments, individual molecular models for everyone and so much more. His true dedication to teaching shows that teaching Chemistry is more than just a career for him, but is also his passion. He often stayed back after lessons for consultations to answer any questions that anyone had, regardless of whether they were from the challenging questions he gave in class or the out-of-the-box questions from the Raffles Academy in school. There were many times when his wife and children were waiting for him to end work (more than an hour after class has ended) but he made sure he completed his consultations. Besides, he would always go beyond what was expected by messaging us to show his concern for our exams immediately after our papers and would give us feedback on our weaknesses one-on-one. Mr Koh is a really inspiring chemistry tutor who gives us confidence in chemistry! Thank you Mr Koh =)

Li Yan, RI 2009 - 2010
(Medicine - NUS)

 

Attending Mr Koh’s chemistry tuition lessons at Twig was probably the best academic decision I’ve made in JC. After I scored a solid U grade for CT1s in J2, I was on the verge of giving up entirely on H2 Chemistry, thinking that I would never ever understand anything. But Mr Koh’s lessons were extremely well-crafted, logical and engaging – learning has seldom been made as fun or satisfying. I attribute my eventual A-level H2 Chemistry A grade to Mr Koh’s patience, dedication and masterful explanations. He really takes the time to ensure each student fully understands the concepts he teaches, and not just memorises the content. Mr Koh is a true first-class teacher, and I will definitely recommend him to anyone who is looking for an excellent chemistry tutor!

Alison, RI 2009 - 2010

 
Twig's chem lessons were fantastic. As dry as H2 Chemistry could get, Mr Koh's passion, enthusiasm and vigor always infected me and the entire class to be extremely interested. Mr Koh was always happy and his teaching was really very interesting! Twig saved my chemistry results. Having attended the lessons and done most of the exercises Mr Koh specially picked out, my H2 chemistry grades improved from a U to a D to an A in both prelims and A levels. I credit Twig entirely for this improvement. Thank you Mr Koh for being so encouraging and caring! I will never forget how you replied all my text messages about chemistry and spent time before and after lessons just to clear all our doubts. Thank you (:'

Xianmin, RI 2009 - 2010

 
It is always a joy being in Mr Donnell Koh's class. His concise H2 Chemistry notes encapsulates all the concepts we are required to master for each topic such as the qualitative explanations, definitions, and mechanisms. His detailed and yet, simple explanation makes learning easy. Apart from that, we are also exposed to additional knowledge and mechanisms that are very useful but yet might not be taught in class. This allows me to comprehend all that i need to know easily and gives me an edge over the others in school. He even goes the extra mile for students, staying after each lesson for us to clarify our doubts so that no student is left behind. 

Under his tutorship, my grades in school improved tremendously, to the point where i got second in school for the mid-year Chemistry exam in JC2. This is certainly a testament to his capabilities as a teacher, and i attribute this to Mr Koh. If you are having difficulties understanding those thick school notes with lots of unimportant materials, fret no more and join TWIG! I strongly believe that he will produce many more outstanding students. THANK YOU MR KOH :-)

Glen Kua Kai Bin, CJC 2010 - 2011

 
Mr Koh, I just wanted to thank you for being such a dedicated Chemistry teacher, really from the bottom of my heart. You’re one of the more effective JC Chemistry tutors I’ve ever had and in all honesty, schools lose out not being able to hire someone like you. Thank you for taking extra time to guide me in the questions that I find hard to grasp. I really appreciate it! Here’s wishing you all the best in life and with that crazy passion for Chemistry… I’ve no doubt about it. Thank you Mr Koh!

Dorcas, RI 2010 - 2011

 
Mr Koh has been one of the most inspiring  teachers I've had in JC. As a highly dedicated and passionate JC Chemistry teacher, Mr Koh has made H2 Chemistry easy-to-understand for his students. Mr Koh is extremely approachable and patient, never failing to answer my incessant chemistry questions. He is also ever willing to clarify my doubts and clear my misconceptions, often asking us after class to stay back and ask him questions should we have any. He never leaves our questions hanging and will always explain the concepts until we understand it. After attending his lessons, I have found chemistry concepts very simple. Under Mr Koh's teaching, I felt fully prepared for A levels. I give Mr Koh full credit for giving me a strong foundation in H2 Chemistry and giving me more confidence to take H2 Chemistry exams, even when the exams have gotten more difficult! Thanks Mr Koh for helping me get an 'A' in every single exam in JC and many Dean's Lists. I couldn't have done it without your help!

Shawn Tan, RI 2010 - 2011

 
Mr Koh is a great and astute JC Chemistry teacher. His greatness lies far within the vast amount of concise notes and practice questions that you will be bestowed to. His astutness lies in his gift in sifting out possible questions that will stand against you during your examinations. Most importantly, he is a tenacious, old-school teacher which deeply believes in constant, harsh drilling which his classes have benefitted much from. I am grateful to meet you. Thanks Mr Koh!

Aristle Tay, TPJC  2010 - 2011

 
Chemistry was never an easy subject for me. Yet, after joining Twig, I began to gain confidence and more importantly, develop an interest in it. This could not have been possible without Mr Koh’s proper guidance and unwavering support. Mr Koh was always able to make difficult things seem simple and this was vital for students like me who did not have a good foundation in the subject. Twig’s notes always came in handy and they focussed on the most fundamental concepts that we needed to know before attempting the questions. An absolutely dedicated JC Chemistry teacher who makes a conscious effort to explain the answers to our queries in as much detail as possible, Mr Koh is the teacher to look for when in doubt.

Mr Koh, thanks for always demonstrating what it means to love chemistry. Your infectious passion for the subject has undeniably inspired me and given me the motivation to work harder in order to do better!

Lynette, RI  2010 - 2011