Being able to identify independent and dependent clauses will help you to decide where to put commas (or other punctuation) in your writing.
An independent clause contains a subject and a verb.
Example: The tree was losing its leaves.
So it is a complete sentence in itself. However, a dependent clause cannot stand on its own. If it is written alone, it doesn't make sense. It is an incomplete sentence. This is because it is usually missing a subject, or a verb or both.
Example: Because of the drought.
We join dependent and independent clauses together to ensure:
- The meaning is clear: The tree was losing its leaves because of the drought.
- The sentence is complete: Because of the drought, the tree was losing its leaves.
Commas are needed to clarify meaning when dependent and independent clauses are added to each other to form complex sentences.
The general rules with commas in complex sentences are:
- If the dependent clause comes after the independent clause (highlighted), no comma is necessary.
Village councils play the main role in resolving disputes and meting out justice. - If the dependent clause is before the independent clause, you need a comma.
Outside of the major cities, village councils play the main role in resolving disputes and meting out justice. - If the dependent clause is in the middle of an independent clause or in the middle of two independent clauses, you need a comma each side of it.
The whole parliament, aside from the President, agreed with the proposed legislation.
Zahra’s family, who had lived in a small village all their lives, suddenly decided to move to the city. Tehran, with a population of more than twenty million, is a busy, chaotic city
Other uses of the comma
- Use a comma to separate the elements in a list.
We need stationery, blackboards and easels for each school.
- Use a comma + a conjunction (and, but, for, nor, yet, or, so) to connect two independent clause
The kittens were very cute, but they were really out of control.
- Use a comma to separate adjectives (descriptive words)
That run-down, dilapidated cottage with the overgrown garden.
- If you can put an and or a but between the adjectives, a comma will probably belong there.
For instance, you could say, "I live in a very old and run-down house."
- Use a comma to set off quoted elements. Because we don't use quoted material all the time, even when writing, this is probably the most difficult rule to remember in comma usage.
Williams (2003) said, “It is highly unlikely that school improvement projects really work as they are intended.”
- Use commas to set off phrases that express contrast.
Some say the world will end in ice, not fire.
- Use a comma to avoid confusion or misunderstanding.
- For most, the year is already finished.
- Woman without her man would be useless.
- Woman, without her, man would be useless
Typographical reasons
Use a comma between a town and a state [Bendigo, Victoria], a date and the year [June 15, 1997],