Read the boy's excuse story. Six verb forms are incorrect. Replace Past Simple form with Past Continuous where necessary. "I left my home when my friend Wendy called me. She asked me to come to her place because she was in trouble. I didn't ask any questions and hurried to her house. While I ran, I met Kate and Jason. They crossed the street. I told them about Wendy and they decided to join me.

When we got to Wendy's place, we rang the doorbell and she opened the door. She cried. Wendy pointed at the tree near the road and we saw a cat. It was Wendy's cat Mars. He couldn't climb down and meowed loudly. I knew what to do. I was very good at PE so it wasn't a problem for me to climb the tree. A few minutes later, happy Wendy held and kissed her dear cat. That's why I'm late, Miss Morgan."

1. I go school five times a week.

2. I visit my grandparents every Sunday .

или    I visit my grandparents just one time a week, on Sunday.

3. Three times a week I'm engaged in musical school.

4. One time a week my brother and I go for piknick at weekends.

5. I watch this serial several times a week.

6. I go dancing on a  discothek one time a week.

Объяснение:

1. Я хожу в школу пять раз в неделю.

2. Я навещаю своих бабушку и дедушку каждое воскресенье

.или:  Я навещаю своих бабушку и дедушку только один раз в неделю, в воскресенье.

3. Три раза в неделю я занимаюсь в музыкальной школе.

4. Один раз в неделю мы с братом ездим на пикник по выходным.

5. Я смотрю этот сериал несколько раз в неделю.

6. Я хожу танцевать на дискотеку один раз в неделю.

1) He lives in the same house (или My friend and I live in the same house, потому что "он живет в том же доме" не звучит). 
2) He studies at the Moscow Law Institute.
3) He is a first-year student.
4) He studies English (или My friend and I study English).
5) Неправильно составленное предложение у вас. Пусть будет 'We are working on making our English better (тогда это Present Continious)', следовательно He is working on making his English better (или My friend and I are working и т.д.)
 6) He is a future police officer (наверное, лучше употребить полиция, нежели милиция. Но можно и милицию оставить).
 7) He should visit his relatives on Saturday (или My friend and I should ...и тд.)
8) Неправильно составленное предложение. Будет 'I hope that I will go to Yaroslavl next summer' и тогда 'He hopes that he will go to Yaroslavl next summer'
9) He doesn't want to do it now.
10) He doesn't know this officer (или My friend and I don't know this officer).
 11) He finished secondary school 5 years ago.
 12) He will (will вместо shall) study many special subjects next year (или My friend and I will study и тд).
13) В году я не жил в Москве? ... Я не поняла, что хотелось сказать. Давайте переделаем на I was on vacation in Moscow last year (я отдыхал в Москве летом) и тогда He was on vacation in Moscow last year.