I guess I'll explain myself to get the ball rolling.
What we teach as 'tenses' are not really tenses but combinations of aspects and tenses. So, present perfect progressive(continuous) is in fact
Present tense + perfect aspect + progressive aspect
Perfect adds the meaning 'before' so since we are talking about the
present perfect here it means
before now. If we were talking about the
past perfect it would mean
before the point in the past I am referring to. Similarly for the future perfect.
I agree with you, Horsa, that there are some problems inherent in the traditional tense system. But I don't think that students should EVER get to that point where they are discussing linguisitic concepts.
For now, I guess that we have to go, somewhat, into the mistakes of the traditional system especially regarding the "future tense" because there is still so much bad info out there.
Generations of ESL learners have been taught a lot of really idiotic things about language and if one looks at a Russian or Japanese or Chinese grammar book on English, we find many of these mistakes.
That's how the Japanese, Russian, Chinese, etc teachers of English have learned about English. It's sad that a teacher should have to spend so much time undoing all the errors of bad prescriptions but that's the reality, so we have to live with it.
The
progressive aspect adds the idea of '
limited in duration'. So to look at a couple of example sentences:
I drive.
I am driving.
In the first there is no limitation on the duration of the verb so it can only be interpreted as being a factual statement. It could answer the question 'How do you get to work?' and would not be referring to any particular time.
The second restricts the time to 'at this moment' and might answer the question 'What are you doing now?'.
How are we then to deal with,
"How are you getting to work these days?"
'Future tenses' are made from combinations of aspects, present verb forms and future markers such as 'will', 'could', 'might', etc.
Future time is often expressed by the use of unmarked present forms: 'going to', 'am doing' etc.
I feel that it is useful to explain the above to students. In my experience it is simpler to explain than the EFL tense system and helps to lead them to a clearer understanding of our language. I tend to do this at intermediate level. I am interested in the opinions of other teachers on this matter.
I generally try to stay away from speaking specifically of 'tenses'. Rather I describe, "We state/talk about finished actions by adding 'ed' to an action. "We state/talk about future actions in many ways" and then I show them a big chart of future structures and tell them, "later, later". "We state/talk about actions now" with [action + ing].
These are, of course, then reinforced with copious amounts of practice in real contexts, to my mind, the single most important aspect of learning a new language.
I recently started teaching a real beginner beginner, the most beginner beginner that I've ever had in my teaching career. Even he had some bad habit to break, some from 'generous' people who had provided him with an old grammar written in his native language, but thankfully, the major problems that I had to overcome were those that his mother tongue naturally cause.