Reading Harmer’s text one can infer that

Read the text to answer question.

No one who speaks English has any difficulty understanding the meaning of a sentence like ‘It’s warm in here’. We all recognise that it is a comment on the temperature in some place or other. But why it is being said, and what the speaker wishes to convey by saying it, depends entirely on two things: the context in which it is said and what the speaker wants people to understand (...) The meaning of language depends on where it occurs within a larger stretch of discourse, and thus the relationship that the different language elements have with what comes before and after them. In other words, speakers and writers have to be able to operate with more than just words and grammar; they have to be able to string utterances together.

Our ability to function properly in conversation or writing depends not only on reacting to the context in which we are using the language, but also on the relationship between words and ideas in longer texts.

Words can also mean more than one thing, for example, ‘book’ (= something to read, to reserve, a list of bets, etc.), ‘beat’ (= to win, to hit, to mix, e.g. an egg, the ‘pulse’ of music/a heart) and ‘can’ (= ability, permission, probability – and a container made of metal). Notice that, in these examples, not only can the same form have many meanings, but it can also be different parts of speech.

With so many available meanings for words and grammatical forms, it is the context the word occurs in which determines which of these meanings is being referred to. If we say, ‘I beat him because I ran faster than he did’, ‘beat’ is likely to mean won rather than physically assaulted or mixed (though there is always the possibility of ambiguity, of course).

(Harmer, 1998. Adaptado)