السلام عليكم ،
When we speak we use a variety of verbal techniques to make our ideas plain. We vary the pitch and tone of voice; we pause or speak faster or slower to get our ideas across as effectively as we can.
Punctuation fulfils something of the same function for the written word.
Full Stops (.)
1 Full stops are used to divide sentence from sentence.
2 They are also placed at the end of abbreviated words, e.g., Hon. Sec.,; Dr.; Nos. 1-5, though it is worth noting that with the advent of word processing open punctuation is now widely used. For example: eg Dr Smith etc.
This is sometimes useful to break up long sentences containing more than one linked idea e.g.:
The worksheet brought the students to a dead stop; they found it very difficult either to understand or to discuss in the time allowed for that particular session.
This introduces a quotation, a list of items or a statement given as an example or an extension of what has gone before, e.g.:
The speech began: \'Workers of the World!\'
At the meeting, we shall need: tables, chairs, a projector .....
The results of their policies were what might have been expected: defeat and disillusionment.
(Nowadays it is often used when writing dialogue too: She said: \'It\'s time we were going\'
Question mark (?)
To be used after any word, group of words or sentence forming a question. But to be omitted from an indirect question, e.g.:
\'He asked me how it was done. \'
To be used:
1 For contractions, to show that letter(s) have been omitted e.g.: of the clock = o\'clock; I will = I\'ll; cannot = can\'t
2 With the addition of s*, to show the possession of someone or something e.g.:
(a) The girl\'s job; (b) all the boys bikes...; (c) the People\'s Republic of China.
N.B. In (a) and (c) we talk of one girl, one people so the apostrophe is before the s. In (b) we talk of many boys so the apostrophe goes after the s.
* Do not add apostrophes indiscriminately after all s endings. In English we often make plurals by adding an s, e.g.:
1 house, 10 houses. In these cases. no apostrophe is needed.
A good general rule for their use, therefore, is to ask yourself if you can roughly substitute \'of or belonging to\' (as in (a), (b) and (c) above). If so, you do need an apostrophe; otherwise you do not.
Whenever the sense demands that the reader should make a slight pause, a comma should be used. e.g. When the results of the poll are known we can take action.
Also to be used to:
1 Separate items of a list, e.g.:
We need to publish articles, organise meetings, leaflet houses and reach the general public in whatever ways we can.
2 In pairs to separate a phrase from the main part of a sentence, e.g.:
The woman, a member of N. U.P.E., stood up to speak.
3 In pairs to enclose words or phrases like, e.g.:
The government, however, refused to ......
The opposition, it should be noted, failed to .....
4 To separate or enclose names or titles from the rest of the sentence, e.g.: