When trying to say “She was not [adjective]”, when do I use “Elle n’a pas été” instead of “Elle n’était”?

Question

To provide some context, I am very new to French and I am still trying to learn simple phrases.

Of course, there are always multiple ways to express the same thing — but, I am not sure if there is a rule that I should know about.

When using Google Translate as a guide, it translates “She was not happy” as “Elle n'était pas contente” … but it translates “She was not entertained” as “Elle n'a pas été divertie.”

Any help is appreciated — Thanks!

Answer 1

The main reason is that "contente" is an adjective and "divertie" is a past participle, which is essentially a verb acting as an adjective. They don't behave exactly in the same way.

It's also possible to have participle that becomes an actual adjective, in that case it's called a "participle adjective".

Answer 2

Elle n'a pas été divertie is a passive voice, but Elle n'était pas contente is an active voice. For _Elle n'a pas été divertie, one could use the active voice elle ne se divertissait pas, which brings back the expression closer to the one, both using the imparfait tense.