Non-native speakers often get confused about what the various tenses
and aspects mean in English. With input from some of the folk here I’ve
put together a diagram that I hope will provide some clarity on the
I offer it as the first answer to this question. Consider it a living
document. Input is welcome, and good suggestions will be
incorporated into the diagram.
Nota bene: What this is not is a discussion of whether there are
more than two tenses in English. We have a dedicated question for
that, to which this
question is not intended to supply arguments one way or the other.
Here, the aim is to provide an overview of what constructions
English-speaking people use for conveying information about actions
referring to past, present, and future, and to provide it first and
foremost to precisely the people who are likely to use “tense” as a
catch-all term in their search, rather than to linguists who know better.
Breaking News There is now an excellent ELU blog article titled
How We Talk About Future
It is highly recommended reading.
A visualization of what we mean in English by the various tenses: