I’ve been attending the free 6-week long Writing Tutorial for Graduate Students at the Writing Centre, and today I learned about coordinating conjunctions.
Coordinating conjunctions are:
But
Or
Yet
So
For
And
Nor
They join “things” of equal value. What that means is whatever are on either side of the conjunctions must be equal. For example, verb conjunction verb, independent clause conjunction independent clause, etc.
I learned that commas after a coordinating conjunction are necessary only when there is a possibility for misreading.
For example, a comma would be needed here: “The police arrested two protesters and a reporter was detained for questioning.”
At first, you might think the police arrested three people, the “two protesters” and “a reporter,” but then you realize “a reporter…” started a new independent clause.
Therefore, this sentence requires a comma: “The police arrested two protesters, and a reporter was detained for questioning.”
A comma is not necessary here: “The weather was clear and the pilot landed.”
But to be safe, if you see a coordinating conjunction, just ADD THE COMMA!
I guess it’s my anal nature, but this is why I enjoy going to my writing tutorials (today was my last day!); I learn so much! People judge you on your writing, and as a non-native English speaker, I gotta compensate 
