Đáp án :

- Thì quá khứ đơn :

$\text{1. They (be) were late for school this morning}$$\\$$\text{⇒ They were not late for school this morning}$$\\$$\text{⇒ Were they late for school this morning }$

- Dấu hiệu : This morning 

- Cấu trúc: (?) :  Was/ Were + S +…?

                   (-) :  S + was/ were + not

                    S : We/ You/ They/ Danh từ số nhiều + were

Cấu trúc thì quá khứ đơn với tobe

( + ) : S + was / were + ...

( - ) : S + wasn't / weren't + ...

( ? ) : Was / Were + S + ... ?

- He / she / it / I / chủ ngữ số ít + was ( not ) + ...

- You / we / they / chủ ngữ số nhiều + were ( not ) + 

` 1 ` . They were late for school this morning .

- They weren't late for school this morning .

- Were they late for school this morning ?

- Dấu hiệu ( của thì QKĐ trong câu này ) : This morning : Sáng nay

- Chủ ngữ là They thì đi với be là were