With regular verbs, forming the present participle requires three easy steps:Conjugate the verb into its 'nous' form, eg. jouer - jouons / finir - finissons / vendre - vendonsNow, remove this ending. This leaves you with the stem of the verb: jou / finiss / vendFinally, add the ending -ant to this stem. This gives you the present participle: jouant / finissant / vendant
Remember, it's not enough just to remove the ending of the infinitive (-er / -ar / -ir) and add -ant. You must find the stem of the verb before you can add this ending (steps 1 and 2)!
Luckily, there are only three verbs that have an irregular past participle: avoir, etre and savoir. You have to learn these, as they don't follow the regular rules!Avoir - AyantÊtre - ÉtantSavoir - Sachant.