How is the past tense formulated in French?

At GCSE, one would need to know two versions of the past tense, the passé composé and the imparfait. The P.C. is used to explain events that happened just once and can be in the near or distant past. It is named as such because it is composed of the present tense auxiliary verb (avoir or être) and the past participle.
The imparfait is used to describe repeated events or states of affairs in the past, and is formulated by taking the 'nous' form of the present tense verb, removing the 'ons' ending, and adding the imperfect endings "ais, ais, ait, ions, iez, aient" for each personal pronoun. The imperfect roughly translates to "used to" in English.