Learn French: Où est le feuillage vert que coupe le jardinier ? - Where is the green foliage that the gardener is cutting?

Both are grammatically correct, but French often swaps the subject (le jardinier) and the verb (coupe) in a relative clause introduced by que. This stylistic inversion sounds more elegant and natural to French ears, especially when the subject is a noun that is longer than the verb itself.

Since the verb coupe comes right after the relative pronoun, shouldn't it be qui instead of que?

This is a classic trap! You must use que because it represents the direct object (the foliage being cut). The gardener (le jardinier) is the one doing the cutting, making him the subject. Even though stylistic inversion puts the verb first, the grammatical roles stay exactly the same. If you used qui, it would grammatically mean the foliage is cutting the gardener!

Would this stylistic inversion still work if I replaced le jardinier with the pronoun il?

No, this specific type of stylistic inversion in relative clauses only works with noun subjects. If you wanted to say "that he is cutting," you must use the standard word order: qu'il coupe. Using inverted pronoun order like que coupe-t-il is strictly for asking questions, not for relative clauses.

I learned that "is cutting" can be translated as est en train de couper. Can I use that here with the inversion?