Давайте разберем каждое предложение и найдем в них ошибки, а затем исправим их.
I used to had Maths on Fridays.
Ошибка: "had" должно быть "have".
Исправлено: I used to have Maths on Fridays.I didn't met him yesterday.
Ошибка: "met" должно быть "meet".
Исправлено: I didn't meet him yesterday.He can sit where he like.
Ошибка: "like" должно быть "likes".
Исправлено: He can sit where he likes.Last Monday we go to the library, we didn't go to the museum.
Ошибка: "go" должно быть "went".
Исправлено: Last Monday we went to the library, we didn't go to the museum.A producer is someone which controls the making of a film.
Ошибка: "which" должно быть "who".
Исправлено: A producer is someone who controls the making of a film.He don't know whose car it is.
Ошибка: "don't" должно быть "doesn't".
Исправлено: He doesn't know whose car it is.We had six lesson last Tuesday.
Ошибка: "lesson" должно быть "lessons".
Исправлено: We had six lessons last Tuesday.Yesterday she caught a cold and fall ill.
Ошибка: "fall" должно быть "fell".
Исправлено: Yesterday she caught a cold and fell ill.A grasshopper is a small insect who has long legs and jumps.
Ошибка: "who" должно быть "which".
Исправлено: A grasshopper is a small insect which has long legs and jumps.
Теперь все предложения исправлены! Если у вас есть дополнительные вопросы или нужно больше помощи, не стесняйтесь обращаться.