Well, the first thing to know is that to form Passé Composé, you need 2 verbs : an auxiliary (AVOIR or ETRE) and a past participle. This matches your perfect tense in English, except you only use the auxiliary "to have" :
- I have walked
- You have done
- He has eaten
If you use a verb that usually ends in -ER (in the infinitive form, i.e. the form you find in the dictionary), then to form the past participle, you need to take away the -ER ending and put -é instead.
For verbs ending in -IR in the infinitive form, you need to take it away and replace it by -i
And for verbs ending in -RE, you replace it by -u.
Mr Vans Tramped
Monter (to go up) and its derivative : "remonter"
Rester (to stay)
Venir (to come) and also: "revenir", "parvenir", "devenir", etc.
Aller (to go)
Naître (to be born)
Sortir (to go out)
Tomber (to fall)
Retourner (to return)
Arriver (to arrive)
Mourir (to die)
Partir (to leave) and also : "repartir", etc.
Entrer (to come in / enter) and also : "rentrer", etc.
Descendre (to go down) and also : "redescendre", etc