"The teaching staff can invite the parents."
Translation:Le personnel enseignant peut inviter les parents.
staff is a collective noun. A collective noun implies a group of things in its singular form. Therefore, it must take a singular verb (like is). There's an exception to this in British and Australian English, where they are considered as plural nouns, so they take a plural verb (like are).
This exception doesn't happen in other languages like Spanish or French, so it's considered a singular noun.
Why can't we say, "Les enseignantes peuvent inviter les parents?"
Yes - I realize this translates to "The teachers can invite the parents.", but that is much more natural to say in English - 'the teaching staff' is a kind of weird formulation that is found when people are trying to sound 'official' (or are a bit old-fashioned).
Is this formulation more common in French?