In French, there are three types of 'if sentence' which we need to worry about:1) If it rains, I will watch TV. (If [present tense] + [future tense].)S'il pleut, je regarderai la télévision.2) If I had time, I would go jogging every day. (If [imperfect tense] + [conditional tense].)Si j'avais le temps, je ferais du jogging tous les jours.3) If I had known, I would have worked harder. (If [pluperfect tense] + [conditional perfect tense].)Si j'avais su, j'aurais travaillé plus dur.The format is effectively the same in English, but it is important to use the correct future/past tenses, like in the examples above.