Cấu trúc thì quá khứ đơn với động từ thường : 
`( + ) ` : S + V-ed / V2 
` ( - ) ` : S + didn't + V nguyên mẫu 
` ( ? ) ` : Did + S + V nguyên mẫu ? 
Cấu trúc thì quá khứ đơn với tobe 
` ( + ) ` : S + was / were + ... 
` ( - ) ` : S + wasn't / weren't + ... 
` ( ? ) ` : Was / Were + S + ... 
- Was not ` = ` Wasn't , Were not ` = ` Weren't 
` + ` I / he / she / it / chủ ngữ số ít + was ( not ) + ... 
` + ` You / we / they / chủ ngữ số nhiều + were ( not ) + ...

` 1  ` . were not - were 

` - ` Mom and Dad là ` 2 ` người ` - ` chủ ngữ số nhiều nên dùng be là were ( not ) 

` - ` Chủ ngữ là They nên dùng be là were ( not ) 

` 2 ` . was - was not 

` V ` 

` 1 `  . Saw - didn't like 

` 2 ` . Did Marco win

`IV`

`1` weren't - were

`=>` Dấu hiệu nhận biết : yesterday 

`=>` Mom and Dad tương ứng ngôi they `->` số nhiều `->` chia weren't

`=>` They là chủ ngữ số nhiều `->` chia weren't

`2` was - wasn't

`=>` The weather là N ko đếm được `->` số ít `->` chia was

`=>` It là chủ ngữ số ít `->` chia wasn't

`------------`

`1` saw - didn't

`=>` Dấu hiệu nhận biết : last night

`2` Did Marco win 

`@` Động từ tobe : I/he/she/it chia was , we/you/they chia were

`+` S + was/were + ... 

`-` S + was/were + not + ...

`?` Was/were + S + .... ? 

`@` Động từ thường : 

`+` S + Ved/V2 + O 

`-` S + didn't + V nguyên + O 

`?` Did + S + V nguyên + O ?