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Usage of the Past Subjunctive 
Formation of the Past Subjunctive 
- The past subjunctive is a compound tense- it consists of two verbs, the auxiliary verb and the past participle one seeks to use in this tense.
- The auxiliary verb is conjugated as if it were being used in the present subjunctive.
- The past participle is added immediately after the auxiliary verb.
- A negative structure such as ne ... pas is always placed around the auxiliary verb, not the past participle.