Punctuation in writing

In written English, punctuation is vital to disambiguate the meaning
of sentences. For example, “woman, without her man, is nothing”
(emphasizing the importance of men) and “woman: without her, man is
nothing” (emphasizing the importance of women) have greatly different
meanings.

In IELTS, test-takers often make punctuation mistakes in
their writing task, from student till advanced learners of IELTS can
make this mistakes. Wrong punctuation become one of the common mistakes
in IELTS Writing Task.

For those who usually make this kind of mistake, you may consider this tips.

1) The last word ends in a period
For example:
“C.E.O.” is an abbreviation of Chief Executive Officer and ends in a period.
Correct: I know that C.E.O. His name is Alan and he used to be my boss.
Wrong: I know that C.E.O.. His name is Alan and he used to be my boss.

2) Comma.
Remember to put comma after the following phrases:
In summary,
However,
To begin,
Furthermore,
Instead,
Firstly,
Secondly,
Even advanced IELTS learners can also make these mistakes.

3) Excessive punctuation.
For example is !!!!!!
This will not create a greater sense of urgency or strong emotion, especially in formal writing.

4) Spacing after punctuation
The rule is after a period or comma, you have to put a space.
For example:
“In summary, happiness is hard to be defined as different people may have very different concepts of happiness.”
After the words “In summary”, we have to put a space.

5) Periods and commas always go inside of quotation marks.
Example: “I think you’re very nice.”
See the period after the word “nice”.

6) When doing this “…” you should use only 3 dots.

7) When using dashes, use two in a row.
For example: Punctuation — 9 Rules.

8) Use no spaces on either side of a hyphen.
For example: We need twenty-four boys.

9) Use a question mark only after a direct question.
For example: May I ask you a question?

Reference: Wikipedia.org; ielts.studyhorror.com