What is it?
The conditional tense can have different values:
A - Condition: the conditional tense is used in a clause A to speak about an event which would take place in the future if certain conditions were met (the condition is either implied or mentionned in a clause B usually starting with "if" and using an indicative tense).
• Si j'avais plus d'argent, je m'achèterais un nouveau sac. If I had more money, I would buy a new bag.
• Nous irions à la plage s'il faisait plus chaud. We would go to the beach if it was sunnier.
• J'aimerais beaucoup avoir un chien ! (si c'était possible). I would really much like to have a dog! (if that was possible).
B - Politeness: the conditional tense is used to make a polite request. It is equivalent to the English "would" or "could". The politeness is suggested by what is implied thanks to the conditional form (often a clause like "if you don't mind", "if you please" or "if that is possible").
• J'aimerais vous poser une question. I would like to ask you a question.
• J'en voudrais trois s'il vous plaît. I would like three of them please.
C - Alleged facts: the conditional tense is often used in journalistic language to speak about alleged facts. By so doing, the speaker reports facts without considering them as definitely true.
• Nous avons appris que le président irait aux Etats-Unis la semaine prochaine. We learnt that the president will go to the United States next week.
• Le chômage serait en hausse de 0.6% ce mois-ci. Unemployement has increased by 0.6% this month. (we have been said so)
D - Reported speech: the conditional tense is used in reported speech instead of the future tense in direct speech. Compare:
• David a dit: "j'irai à Soho ce soir" > David a dit qu'il irait à Soho ce soir. David said he would go to Soho tonight.
• Elle a dit : "ça ne me dérangera pas" > Elle a dit que ça ne la dérangerait pas. She said she wouldn't mind.
How is it formed?
• take the infinitive form of the verb;
• For verbs ending with "-re", delete the "e";
• Add the unique endings below to the stem.