French verbs are a complex area of French grammar, with a conjugation scheme that allows for three finite moods (with anywhere from two to five synthetic tenses), three non-finite moods, three voices, and three grammatical aspects. Ultimately, verbs have seven simple tenses (present indicative, imperfect indicative, simple past, future indicative, present conditional, present subjunctive and imperfect subjunctive) and seven complex tenses (the perfect forms of each simple tense).
The simple past, imperfect subjunctive, and their compound tenses, however, are rarely used in modern French. In addition, the imperative mood derives conjugation normally from the present subjunctive.
Read more about French Verb Forms. [Source]
Désolé.
Sorry.
J'
appelle
la
police
I am calling the police.