How do I formulate the conditional tense?

The conditional tense is a bit like the future tense but with different endings. You use the stem of the verb and add on the conditional endings (the same as in the imperfect tense).

and example would be the conditional of the verb vouloir- to want:

je voudrais

tu voudrais

il/elle voudrait

nous voudrions

vous voudriez

ils/elles voudraient

(the stem voudr is the same as in the future tense which is as follows- je voudrai, tu voudras, il/elle voudra, nous voudrons, vous voudrez, ils/elles voudront ; the endings are the only thing that is different)