Contents introduction chapter the verb. Basic grammatical categories of the verb

1.2. Special Forms of the English Verb.
With the help of the species category, a person differentiates knowledge according to its source: we know about something because we saw (heard, felt, etc.) it ourselves, and we know about something because this knowledge was transferred to us in ready-made (someone said, read about it, learned at school, etc. the possibilities here are very diverse). This distinction is very important, and in our daily activities we take it into account at a subconscious level all the time. We all know the proverb "Better to see once than to hear a hundred times". That is, what is seen with one's own eyes, as a rule, is not questioned, while knowledge obtained from the hands of others is not always necessarily reliable. In this regard, look what happens if, in the above situation, the boy uses the imperfect instead of the perfect form of the verb: "Mom, dad came!". Although formally this statement is grammatically correct, in our situation it cannot be used, because it is not said so. And they don't say that because he came does not contain an indication that at the time of the utterance the boy sees his father, while the form "arrived" contains such an indication.
The difference between the Russian language and English lies in the fact that in Russian such semantic differences are very often conveyed not by special forms of the verb, but by the context. Compare the following examples: "Ben smokes, despite the doctors' warnings" and "Look, Ben smokes again, despite the doctors' warnings." In the first case, we are talking about what we know about Ivan, while it is not at all necessary that Ivan be in front of our eyes: he may even be in another city. In the second case, we are talking about what we directly observe: this is directly indicated by the verb "look." In English, everything is much simpler, because there these semantic differences are conveyed by special (specific) forms of the English verb: Simple and Progressive, respectively. Note that the term view comes from the verb "to see" (which is etymologically related to the Latin “videre” - to see and the Greek “eidos” - that which is seen).
But so far we have been talking about two types of knowledge, which correspond to two types: one knowledge has a definite source of information (for example, the boy in the above example), and the other has an indefinite source (for example, when I say "Ben smokes", I do not make it clear where I knew that). And there are four forms of the English verb. Why so much?
Yes, because the situations when we talk about what we directly observe can differ significantly, depending on what exactly we see, hear, etc.). When I say: "Look, Ben is smoking again", I have the opportunity to observe the smoking process itself (he holds a cigarette in his hand, brings it to his mouth, draws in the smoke and then releases it). But if mom, meeting Ivan, smells the smell of smoke emanating from his clothes and asks: "Have you been smoking again?", she asks a question based on what she perceives at the moment of speech (in this case, by the sense of smell), and this, of course, the present tense of the verb. But she does not observe the very effect of smoking, only certain signs are available to her perception, indicating that Ivan smoked. To express this cognitive meaning in English, there is a special form of the English verb - Perfect.
This form is used when we compare what we see with what happened before (for example, Ben did not smell in the morning, but now he smells of tobacco, which means he smoked). Finally, there are cases when we are talking about a directly observed action and at the same time we are comparing what we see with what we saw at some moment (or at some moments) before. For example, I see Ben smoking now, but I also saw him smoking before that, all day long. In this case, the two forms of the English verb are combined, expressing different cognitive meanings, and we get the Perfect Progressive form, which is very disliked by many students, although in fact it is not simple, but very simple.