Is it normal for my teenage son to be grouchy all the time?

I was grouchy until I was 18.

With the SATs etc, college pressure, so much homework, studies, friends, parties, school drama and projects, not to mention staying up at night, your son probably works harder than you. Chill. Some people prefer having their own company.

Pretty sure that's 99.9% of teenagers

Monosyllabic, secretive, bizarre, unreasonable & moody are all behaviours to expect from teenagers. Don't expect normalcy from your kids until they turn 30.

Buy him drugs its not his job to entertain you

Hang in there until he's 18, then you can tell him to go away.

Teenagers are often miserable company. Too many possible reasons for that to list here.

It's unlikely that pestering him will result in him explaining the reasons for his negative attitude. It's entirely possible he doesn't even understand it himself.

The human brain doesn't stop developing until around the age of 23, so it might help to know that he's not yet a finished product. Most teens who are a complete pain in the backside grow up to be relatively decent human beings.