Breakdown of Ha comprato queste pantofole e se le è messe.
e
and
queste
these (feminine)
comprare
to buy
se lo
it for himself/herself/themselves (se la, se li, se le)
Questions & Answers about Ha comprato queste pantofole e se le è messe.
Why is it se le and not si le?
When the reflexive pronoun si (meaning "on herself" here) is combined with a direct object pronoun like le (them), the si changes to se. So si + le becomes the combined pronoun se le.
Why does the second part use è (essere) while the first part uses ha (avere)?
The first verb, ha comprato (bought), is a normal transitive verb that takes avere. The second verb is mettersi (to put on oneself). Because it is a reflexive verb, it must take the auxiliary verb essere in the past tense.
Why does the sentence use messe instead of messo?
Because of the direct object pronoun le! When you use a direct object pronoun (like lo, la, li, or le) before a compound tense, the past participle must agree with it in gender and number. Since le replaces queste pantofole (feminine plural), the participle becomes messe.
Could I just say le ha messe instead of se le è messe?