There are three main uses of language:
i) to express facts and information, eg "It's 10 am". "My birthday is 8th November." "At the moment the Prime Minister of UK is David Cameron".
ii) to express emotion and opinion, eg "He is silly". "She is pretty". "I like Marmite". "That's a remarkable dress!"
iii) to get people to do something, eg "Keep off the grass". Your appointment is at 1230". "Be quiet". "Vote for strike action!"
So far so good. But the uses overlap. Any of my examples could be in any of the other categories if the situation is suitable.
For example, "It's 10 am" does give information (i) but it could also mean something like´'It's time you got out of bed" - usage (iii) if, say, a wife said it to a husband who was still in bed when he should be at work! She might also be saying, "Get up you lazy so-and-so and go to work."(usage ii her opinion about him as well as usage(iii) telling him to go to work.
And the person who says, "George is silly" (usage ii, expressing opinion) probably wants his listeners to think the same about George - usage (iii) 'to get someone to do something'.
There is some fact in almost all speech. The union official who tells an audience to "We need everyone to vote for Strike Action" is perhaps reminding the members that a majority vote is needed before a legal strike can take place - usage (i) expressing fact and information as well as urging them to do it - usage (iii).
The problem for the reader (or listener) is to work out the relative importance of the three factors in order to fully understand the meaning of a particular text (conversation).
The full 'Meaning' of what is said depends on the whole situation, and the relationships of the people in it as well as the speaker. Therein lies the fun we get from reading and from conversation.
