The use of the “en” pronoun

Question

My French teacher taught me that when you are asked to replace any noun followed by “de”, always use the personal pronoun “en”. However, I presumed that she was always referring to any noun followed by the article partitif “de” and not the preposition “de”.

How would I replace “de son pays” in the following sentence:

Elle te parle souvent de son pays.

Also, please explain the usage of the personal pronoun “en“ in this context.

Answer 1

You can say "Elle t'en parle souvent". Explaination : "Elle te parle souvent de son pays" you can ask the question "Elle te parle souvent de quoi ?" The answer is "De son pays", obviously. Then you can say "en" instead of "De son pays". This is named COI (Complément d'Objet Indirect).