Reply #14: From a teacher

[AnnInLa]

I'm a teacher....of math....that's why I can't spell or write gramatically correct sentences. But, I know, that unless the whole sentence is very short, you do put a comma before the conjunction in a compound sentence....and usually in a complex sentence. If my students are trying to write a paper or paragraph for a grade, I tell them to read their sentences very slowly to themselves, and where they feel a natural pause, then stick a comma in there.

If you choose not to use the conjunction in a compound sentence, then put a semi-colon.

P.S. The word "like" should be, but doesn't have to be, replaced with "as if." (for formal writing)