The most important thing with punctuation is to make sure your sentences are correctly marked at the start and end.
The starts are easy - they should all have capital letters. Check through to ensure that you have done that and correct any mistakes.
The endings must have full stops or an equivalent such as a question mark or exclamation mark. All sentences must end with one of these. If you find yourself using a lot of commas, you’ll probably find your sentences are way too long and that your commas need to be full stops.
Commas are only used inside sentences to add a pause and emphasis to parts of the sentence, helping your reader to read it as you intended. Avoid over-long waffly sentences at all costs as these give writing a deadening quality and you need liveliness!
A very effective proof-reading technique is to read your work out loud pretending it is a play-script you are practising as an actor. As you read you will hear yourself speaking your lines and will soon notice if sentences are over-long or need better punctuation. Even misspellings and repeated key words will stand out like sore thumbs using this technique.
After a little practice you won’t need to read aloud, you’ll be able to read the lines in your head and still find any errors – perfect for proof-reading exam answers.
Other areas which often cause problems are speech marks and apostrophes.
If you have included dialogue - the words that somebody speaks – make sure that you put them all inside speech marks along with any punctuation they need (ie treating them as normal sentences but inside speech marks). Remember to close the speech marks as well as open them and to add a final punctuation mark or, at the least, a comma. Remember, too, to give each change of speaker a new paragraph.
John ran in obviously out of breath. “I don’t suppose,” he puffed, “that you’ve seen Ellie? I can’t find her anywhere!”
I was worried but I didn’t want to alarm him, “No I haven’t John. Is she really that late?”
Apostrophes have two uses: