Learn Farsi: این حرف عالی نیست. - These words are not excellent.

The noun حرف can mean "word," "speech," or "talk." In Farsi, you typically use the singular phrase این حرف (literally "this speech" or "this talk") to refer to an idea or what someone just said. In English, it often translates more naturally as the plural "these words."

I'm learning about compound verbs right now. Is حرف part of a compound verb in this sentence?

Not in this specific sentence! While the noun حرف is the main ingredient in the very common compound verb حرف زدن (to speak / to talk), here it is simply acting as a standalone noun (the subject of the sentence).

Where is the verb in this sentence?

In Farsi, the verb almost always goes at the very end of the sentence. Here, the verb is نیست (is not). It is the negative form of است (is).

How would I change this sentence to say "These words are excellent"?

You just need to swap the negative verb at the end for a positive one. Replace نیست (is not) with است (is), making the sentence: این حرف عالی است.