`1.` I have learnt Spanish for three years.

`-` It's + time + since + past simple clause.

`=` S + have/ has + Vpp + for + time.

`-` learn - learned/ learnt - learned/ learnt: học

`2.`  My friends have difficulty in understanding Australian’s accent.

`-` Cấu trúc: S + have (biến đổi) + difficulty + in + V-ing

(gặp khó khăn trong việc gì)

`-` Tạm dịch: Bạn bè của tôi gặp khó khăn trong việc hiểu giọng của người Úc.

`-` Thì hiện tại đơn: S + V(s/es)

`-` "My friends" là ngôi số nhiều nên "have" nguyên mẫu.

`3.` Because of being sick, Tin did join the summer camp.

`-` Clause (kết quả) + because + clause (nguyên nhân)

`=` Because of + N/ N phrase/ V-ing (nguyên nhân), clause (kết quả)

`4.` When you were young, were you able to speak English?

`-` To be + S + able + to V? : có khả năng làm gì

`=` Can/ Could + S + Vinf? : có thể làm gì

`-` Thì quá khứ đơn: Was/ Were + S + ...?

`5.` Three hundred students took part in the swimming competition last year.

`-` take part in (v); tham gia

`-` DHNB: last year `=>` Thì quá khứ đơn

`-` Công thức: S + Ved/ V2

`-` take - took - taken

`1` I have learned Spanish for three years 

`=>` It's + khoảng thời gian + since + S + Ved/V2 + O 

`=` S + has/have + Vpp + O + for + khoảng thời gian 

`2` My friends have difficulty (in) understanding Australian's accent 

`=>` It's difficult for someone to do something 

`=` S + has/have + difficulty (in) doing something : gặp khó khăn trong việc gì đó 

`3` `-` Because of being sick, Tom didn't join the summer camp 

`-` Because of Tom's sickness, he didn't join the summer camp 

`=>` Because + S + V + O 

`=` Because of + N / N phrase / Ving : bởi vì 

`4` When you were young, were you able to speak English? 

`=>` Could do something `=` tobe able to do something: có khả năng làm việc gì đó 

`5` Three hundred students took part in the swimming competition last year 

`=>` enter`=` take part in : tham gia vào