The punctuation mark full stop (.) is used to close sentences. A new sentence that follows a full stop has a capital letter.
- Honesty is the best policy.
- Sweet are the uses of adversity.
- A friend in need is a friend indeed.
Full stops are also used in writing abbreviations. This is becoming less common in British English.
Examples are: oz. for ounce (s), Prof. for professor, i.e. for in other words and e.g. for for example.
Question marks (?) are used to close direct questions. A new sentence that follows a question mark has a capital letter.
- What are you doing?
- Did you get my letter?
- Why do we try to reach the stars?
Note that we do not use question marks after indirect questions.
- He asked me if I had received his letter.
- I asked her what time it was.
The exclamation mark (!) is placed at the end of an utterance which is an exclamation or which merely expresses strong emotion.
- What a lovely painting it is! (exclamation)
- How beautifully she sings! (exclamation)
- You must leave at once! (strong emotion)
- I can’t believe this! (strong emotion)