Определите в этих предложениях видовременные формы глагола - сказуемого и укажите их инфинитив. last year they increases their production. he signed a few contracts last summer. he thinks of starting his own business. this company will make a big profit next month.

1increased(у тебя ошибка!)-Past SimpleActive.
инфинитив to increase.
2signed-Past Simple Active.
to sign
3thinks-Present Simple Active.
to think
4will make-Future Simple Active
to make