1. has learnt

=> Thì HTHT; DHNB: for three years. Chủ ngữ 'the boy' số ít đi với has + V_pII

2. will give

=> Câu điều kiện loại 1: If + S + V _s/es, S + Will/can/shall/..+ V

3. wasn't

=> Yesterday -> Thì QKĐ 

Đáp án:

Giải thích các bước giải:

1. The boy has learnt for three years,but he can't understand this letter.

2. If I see him, I will give him a lift

3.I wasn't very happy yesterday

Chucbanhoctot!