1 Ann is going to school now.
2 He plays the guitar every day.
3 Jane and Sam are reading a book now.
4 Dad is washing his car at the moment.
5 He walks his dog in the evening.
6 Olga plays tennis in the yard.
7 We are drawing funny pictures for our friends' birthday party now.
8 He always does his homework after school.
9 I'm not doing an English exercise now.
10 Tom usually reads a lot.
11 Listen! Sandy is singing in the bedroom.
12 My mother is making lunch now.
13 My sister never helps in the kitchen.
14 Sarah sometimes reads classic.
15 They rarely watch TV in the morning.
16 They often clean the garage.
17 Look! The boys are coming home.
18 His cousin goes for a walk every day.
19 I'm chatting online at the moment.
20 Cats eat mice.
Вообщем смотри, здесь сравнивается 2 действия (времени); Настоящее простое и настоящее длительное.
Настоящее простое - это выполнение привычных дел и действий "по жизни". А настоящее длительное - это выполнение действий в данный момент, (сеюсекундно).
И смотри на "маркера" - это слова указатели. Они чётко указывают на конкретное время. (Now - сейчас или Every day - каждый день).
Ничего сложного нет. По сути разговорная база английского с этих правил и начинается.