Пожалуйста помогите! Даю 20 баллов! Пожалуйста

1) Perhaps I will buy my best friend the 'Harry Potter' book as he's fond of it.
2) I expect that tomorrow afternoon at 3 o'clock I will be going out with my friends.
3) I believe my elder brother would help me studying for exams.
4) I think I will spend my holidays in the country with my relatives.