the gerund and the infinitive can you help me

[syma]

السلام عليكم ورحمة الله تعالى وبركاته
what is the difference between this examples in the meaning
he finished playing tennis
he finished to play tennis
he suggests to leave
he suggests leaving
also the teacher tell us that the verb finish, suggest and other verbs like enjoy practice ........are used with the gerund but not by the infinitive, however,he uses finish with the infinitive
can you explain me