The Formation of the Present Conditional
    The present conditional in French is formed similarly to the simple future. For regular verbs, you add the endings of the imperfect to the infinitive. So the conditional paradigm for parler would be:
Je parlerais     Nous parlerions
Tu parlerais    Vous parleriez
Il parlerait      Elles parleraient

Finir would be: Je finirais, Tu finirais, etc.

With -re verbs, as long as you remember to drop the e at the end of the infinitive, the formation is regular. So: Je prendrais, tu comprendrais, elle vendrait, etc.

There are of course verbs with irregular futur-conditional stems (for instance être/ser--, avoir/aur--, aller/ir--, etc.), but the endings remain regular. So: Je serais, tu aurais, il irait, nous ferions, vous voudriez, elles pourraient, etc.

The Use of the Present Conditional
Generally speaking, you will use the present conditional to be polite and to express something possible or unreal (contrary to fact).

Formulas of politeness frequently involve pouvoir and vouloir. For instance: "Est-ce que vous pourriez m'aider, s'il vous plaît?"; "Je voudrais une table pour deux, s'il vous plaît."

To express the possible or the unreal, the present conditional can be used all by itself (for instance: "A ta place je prendrais de l'aspirine"), or with an explicit condition introduced by si ("Si j'avais mal á la tête, je prendrais de l'aspirine").