How do I form the pluperfect tense?

The pluperfect tense is used to describe an action that happened further back in the past - something you "had done". Here's an example: tu étais partie quand je suis arrivée (you had left when I arrived)To form this tense we simply take the imperfect form of the auxiliary verbs 'être' (étais, étais était, étions, étiez, étaient) or 'avoir' (avais, avais, avait, avions, aviez, avaient) and put them in front of the past participle of the main verb. Remember to make the verb agree with 'être' - if it's feminine add -e, if it's plural add -s and feminine plurals -es!So if we wanted to say "Jean told me that she had gone on holiday" it would be "Jean m'a dit qu'elle était partie en vacances." Note that we're using 'était' because partir is an être verb and 'partie' has an -e on the end because it's feminine.