A teacher – English not Chinese – today asked me if I could give him a quick run down of the English tense system, as he isn’t confident of his grammatical knowledge. This isn’t at all uncommon here. In fact, as someone who actually has more than the most basic grammar knowledge, I am very much the exception rather than the rule when it comes to foreign teachers.

Trouble is I don’t really know where to go with this.

I could explain to him in detail about tense, aspect, voice and mood. I could show him that English really has only two tenses, as such – present and past – and that what we commonly think of as the future is really formed with the modal “will”. I could explain why anybody who says the passive must not be used is an idiot (though I’d have to get that explanation of “voice” done first.)

The trouble is, I’m a teacher here myself and I know that this isn’t what he needs. I don’t even know how I should tackle these things with my students. The Chinese grammar books are all at odds with my understanding of this area and the important thing to a student here isn’t that he is any good at English, it’s that he can pass his exam and go to University.
And I’ve gone on at length before about why a good knowledge of English grammar actively works against Chinese students in exams.

Imagine how much harder it will be for a teacher that got his grammar second-hand from me to make the call on what to pass on to the students.

Of course I could teach it to him as I learned it in school - where pretty much everything I was ever told was wrong. I could teach that English has twelve tenses (which is what my teachers told me) – the various combinations of what I now know to be present, past, future (modal will) with continuous/simple/perfect aspects. Of course that would be ignoring mood (no great loss there) and voice (a rather more substantial loss).

Or I could just do a “lies to children” version giving him just the information that he needs to pass on to his students to get them through the exams.

He’s not a stupid guy, but he does suffer from having gone to school in England in that period when the powers that be had decided that grammar should no longer be taught, so he lacks even the very basic stuff like a broad understanding of what a noun or a verb is. He’s actually a pretty good teacher for the job we do. He gives the students interesting discussion tasks, has a great connection with them and works hard in the classroom. His need is more perceived than actual, as we are discouraged from teaching grammar. All the same grammar questions come up – especially with private students – so he wants to understand well enough to answer them.

But what is well enough?

What would you tell him?

And while I think about it, many of the Chinese grammar books still have the specious distiction between "shall" and "will" - insisting that I/we should use "shall" for futurity and "will" for intention while you/he/she/it/they should do it the other way round.
Perhaps the most idiotic non-rule ever created.
Should I also tell him that?

An interesting problem, Bob. Here's my two cents.

First, the problem is one of terminology. The teacher asking the question says tense, and you immediately think of tense, aspect, mood, and voice. By tense, I find that most people mean something like conjugation. That is all the different verbal forms (either inflectional one word forms or periphrastic ones, i.e., teach paradigms) and how they are used.

I guess I would present the teacher with a fait accompli, i.e., give him the best description of what the present-day English grammar of verbs is and how to use them. Use a consistent terminology that agrees with how you analyzed the situation. Later on, cover what other teachers may mean when they use the terms differently from you. Then cover the outlying cases where, others may try to analyze the verbal system differently from yours and prohibit perfectly good forms, e.g., non-use of the passive, the old shall/will chestnut, etc.

This is pretty much how old / traditional reference grammars of Latin, Classical Greek, and Sanskrit were organized. Give all the explanations and paradigms (declensions and conjugations) up front and later discuss how they were used and what they meant. It's funny that even a heavily inflected language like Latin had some periphrastic verbal forms (cf. the English modal system), i.e., the passive forms of the perfects, e.g., amor 'I am loved' vs amatus sum 'I have been loved'. Nobody ever suggested that Latin does not have passive in certain parts of its paradigms comparable to what some people say about English tenses.

Now whether this teacher will sit still for that, who knows? But at least my conscience would be clear. Oh, and good luck!

Wow, that is quite the conundrum, Bob, particularly since he is an English teacher. And it's quite a compliment to you.

Of course, I am not qualified to answer this question, but z's thoughtful answer seems reasonable. Having been a professor, however, I think maybe you should teach him on two levels. One, the way z advises and for his own learning. However, secondly, his students need to pass. What essentially does he need to know about tenses (and grammar) for the students to pass. Being inquisitive, I think he'd appreciate that two-pronged approach. I know I would. I'd feel a responsibility to my students, but a thirst for learning more from a brilliant individual whom I've been so lucky to be teaching with. I suppose it's formally called a "mentorship."