3 basic categories of the verb: aspect, correlation and voice. They are constituted by 2 forms of the verb – analytical and non-analytical. The categories of mood, tense and person are basically different. They are characteristic of only finite forms of the verb. The category of tense, being a predicative category, differs from other categories in its structure, grammatical meaning and its syntactic function because it is connected with the essence of the speech act, with interpersonal relations.
The opposition of past and present is not the opposition of just 2 verbal forms but the opposition of 2 systems of forms:
Present:
Past:
works
worked
is working
was working
has worked
had worked
has been working
had been working
is going to work
was going to work
is to work
was to work
Functionally all the forms, entering these two systems, are the same. They’re used in the syntactic function of the predicate in the sentence. But in speech in the plane of communication the present forms reveal their specific character: they reflect facts and evens as actual, immediately related to the participants of the speech act. On the contrary, the forms of the past reflect something that is already the past, history, not immediately related to the participants of the speech act. What is represented by the past forms is of some cognitive interest to the addressee.
If we admit that the tense forms of the present express reality and make the information actual for the participants of the speech act, it is possible then to account for the rule ‘in clauses of time and condition forms of the present are used instead of the future’ (though the verb expresses a future action). The same is relevant for the use of the forms of the present in object clauses after the verbs with the meaning know, learn, find, imagine, see (that), look, take care, mind, etc.:
The problem of the future tense: will+Infinitive.
- An instant or spontaneous decision to do something.
- Predictions of a general character
- Requests, promises, threats, offering help, etc.
Other ways to express a future action: Present Continuous, going to.