Are there any plural words that don't have a singular?

Series. As in The World Series. Can there be only one serie? sery?

Single is nice. Female and single is nicer. Female and single and in the DFW area is nicer still.

Hey, I can hope, can’t I? (Don’t answer that!)

“wrought” is past tense for “work”.
Example: wrought iron. You don’t wreak the iron, you work it.

Probably “the weather”, although it would depend on the context.

One is said to have “wrought” vengence. I don’t work vengence, I wreak it.

Perhaps those who use “wrought” this way are wroung–although, I think God wrought some in the Bible

Ever tried to write and not use sexist lanuage? You can’t say “he” when talking generally, and “he/she” is a pain, but there is no good alternative.

Nothing. This is a case where the requirements of grammar overrule semantics. The sentence requires a subject, even though semantically all that’s important is the verb. So we put in it as a placeholder subject. French does the same thing, but since there is no neutral gender in French, they use the masculine pronoun.

I’ve noticed for about 10 years add copywriters often refer to “a jean” or “a pant”. Sounds really funny, though.