посчитайте назавтра очень надо Короче надо эти предложение разобрать в simple tense, на 3 вида, тоесть Past, present, future, надеюсь понятно объяснил

1) they went to mountains last year

they will go to mountains next year

they have already gone to mountains.

2) dog played with it's toys

dog will play with it's toys

dog has played with it's toys

3) Shark swam very fast

shark will swim very fast.

shark has swum very fast