It's such a pleasure to have students who are motivated to learn, and curious about the language. With students like these, lessons seem to just hum along all by themselves.

However, there is the little problem of how easily these enthusiastic learners can catch you out with curveball questions. For me, I find the vocabulary questions most difficult: 

 “Teacher what's the difference between to ask and to question?”
“Teacher, is exceed the same as excess?”
“Should I use pupil or student?”
“Are commence and begin the same? And continue and resume?”
“Do merry and happy and enjoy mean the same?”
“How are hotel and guesthouse different?”

What should we do here? Answer the question, or brush it off? By brushing it off, I mean saying something like “They're the same”, or “Oh, one's American and the other is British”. The student will most likely accept these gestures – but this is stretching the truth for convenience. On the other hand, answering the question leads to two problems. Firstly, quite often the level of abstraction far exceeds what the less motivated learners in the class can cope with. So do you stop the class to deal with the questions, even at the risk of confusing everyone else? Secondly, the questions are usually off topic, and while it's a real pleasure having this kind of curiosity, it unfortunately detracts from the real focus of the lesson.

I find these off-the-cuff questions students throw around difficult to answer quickly and convincingly. The trick is to identify the difference simply and succinctly. Having failed with this alarmingly (and embarrassingly) a few times, I've come up with a little checklist that I run through when these kinds of questions arise in class:

Part of speech: in some cases, things are simply a matter of a difference in the part of speech. In the examples above, exceed is a verb, and excess is a noun. No problem. The same works for enjoy – a verb – and happy and merry - adjectives.

Denotation: sometimes the difference between two words is a real difference in meaning. This is what the students are most often looking for. In our examples above, continue and resume differ in their denotation. The difference is subtle: resume implies that activity has stopped, while continue doesn't. In the classroom, this difference is best given through an example: “Classes will resume after festival” or “Classes will continue as usual (so please ignore the festival)”.

A cline: for some word pairs, the difference can be most easily explained as a matter of intensity. This might be the case with guesthouse and hotel. We could add hostel here, and make a cline (or ladder) of how expensive the place is for a tourist. On the board, our cline may look something like this.

It's not perfect, but it provides a neat visual of the differences in the meanings of these words.

Collocation: sometimes two word pairs look like they are true synonyms, but in fact they act quite differently in that they bond (or collocate) with other very specific words. For example, merry collocates strongly with 'Christmas', while happy collocates more strongly with 'birthday' and other festivals.

Register: the words mean the same, but one has localized use, and is therefore less common. In the examples from my classroom, begin and commence differ in formality. We would only expect to find commence in fiction and academic texts, for example, and is used less frequently.

Connotation: certain words have a specific 'feeling'. Consider plump, as opposed to fat. One has a more insulting connotation. From the examples above, to ask and to question differ in their connotation. To 'question' someone has the feeling of suspicion and doubt, and may fit more naturally into a police or detective story. We can also apply connotation with the pupil/student pair, because pupil carries a connotation of youth.

Try it out. Using my list to identify the possible differences between two close synonyms, have a crack at dealing with these other questions from my students:

• Is salary and allowance the same?
• Is there a difference between blame and criticize?
• Side order, or side dish?
• What about cooperate and collaborate?
• Is start the same as begin?
• What about characteristic and personality?
• Are force and compel the same?
• Is tolerance the same as endurance? How are they different from patience?
• Intend or desire?
• Should I say gaze or look?
• Insult and offend?
• Is choose the same as decide?

And as a bonus for long termers in Thailand:

• Does porjai mean pleased or satisfied?

A great many students don't ask these questions. But there are a few for whom this becomes something of an obsession. In my experience, students' tendency towards 'word-pair-itis' is exacerbated by the use of dictionaries that are too difficult for them. It might help getting these learners to use a learner's dictionary. I like the Meriam-Webster version (www.learnersdictionary.com).

In addition to a simple definition, this site gives a few example sentences for students to see the word in context. They are American contexts, but hey! Try it out using the example of gaze: you'll see it highlights the meaning of 'a long time', and goes on to contrast (for these synonym junkies) other closely related words like gape, stare and glare. It also gets the students constructively using their phones (see this cool blog), and allows you to get on with the task of actually focusing on the lesson for everyone else.

Steve has been a teacher and teacher trainer for over 30 years, and is currently a lecturer on the Master’s in TESOL program at King Mongkut’s University of Technology Thonburi in Bangkok.