Learn French: Elle n'a pas oublié son parapluie hier. - She did not forget her umbrella yesterday.

In the passé composé, the negative words ne and pas form a sandwich around the helper verb. Here, the helper verb is a (has). They don't go around the main action word (oublié). So, you say n'a pas oublié, not n'a oublié pas.

Why is it n'a instead of ne a?

When ne is followed by a word starting with a vowel, like the helper verb a, the e is dropped and replaced with an apostrophe. This makes the phrase flow better and is required in French before verbs starting with a vowel.

Because the subject is a woman (Elle), shouldn't 'her umbrella' be sa parapluie?

This is a common trap! In French, possessives like son and sa match the gender of the object being owned, not the owner. Since parapluie (umbrella) is a masculine noun, you must use son, even though it belongs to a woman.

Why does the English translation use 'did not forget' instead of 'has not forgotten'?

The French passé composé can translate to both 'forgot' and 'has forgotten'. English usually uses 'did not forget' for completed past actions when a specific time like hier (yesterday) is mentioned. French simply uses the standard passé composé for this.