Choose the one that is NOT grammatically correct.

1. My friend coughed for more than ten minutes.

2. My friend walked in the park for thirty minutes.

3. My friend was kicking the wall for half an hour.

4. My friend built a house for three months.

5. My friend was reading a book for three hours.

It is from my grammar work book.

The answer is 4. According to the book, in the fourth sentense the 'for' should be changed to 'in'.

But, is that correct just itself? dose it make sense just itself?

And I don't understand the differences between '4' and the others.
Compare 2 and 4. "Walking" is an ongoing activity which you can stop at any time, like exercising. "Building a house" is not finished until the house is "built."

"For" is used in describing how long you spent performing an activity. "In" is used in describing how long you spent achieving a goal, or reaching an objective, or accomplishing a task.

If his goal is to walk three miles, you may say, "My friend walked three miles in the park in thirty minutes."

"I got my bachelor's degree in three years." "I worked on my bachelor's degree for three years, but I finally gave up."

You may say, "My friend worked on his house for three months." The house is not yet "built."

My friend built a house in three months. The house is now a house. He finished his task. The house has been built.

- A.
AvangiYou may say, "My friend worked on his house for three months." The house is not yet "built."

Thank you, Avangi! I began to wonder if it was possible at all to convey this meaning in English when I looked at the original poster's sentence, in which built was used. I didn't automatically realize that the verb must be changed in English! In Finnish we would use the equivalent of the verb build and simply put house in the partitive case and that would convey the idea that the building hadn't been completed.

Site Hint: Check out our list of pronunciation videos.
Coughing, walking in the park, kicking the wall, and reading a book are all activities.
Building a house is an accomplishment.

States and activities can be accompanied by for clauses of time. Accomplishments and achievements cannot.

The following are unusual for the same reason. They are accomplishments or achievements.

Catherine hung her coat on a hook for three hours.
Pete drank a glass of water for five minutes.
George won the prize for fifteen minutes.

Teachers: We supply a list of EFL job vacancies
Thanks, everyone!