Grammarcheck.net recently posted this infographic of 21 frequently ignored (or unknown) grammar rules and writing mistakes that everyone who writes should know.
How many do you know? How many do you ignore?
I’m with them on all but the serial comma and semicolon. I only use a serial comma for clarity in my writing. And, I think the semicolon is too formal for my voice. I only add it when my copy editor insists.
Source: www.grammarcheck.net
Question: The couple has? The couple have?
that’s a tricky one. I think you use has Couple is considered singular even it is two people. Before you send a manuscript off, I’d double check with a grammar guru. I always use a copy editor because there are so many rules andasmany exceptions.