Mr.Smith must sign all these letters

=> All these letters must be signed by Mr.Smith

I advise you to put your money in the bank

=>You'd better put your money in the bank.

( had better: nên ) 

`1` All these letters must be signed by Mr.Smith

`=>` Bị động - V khuyết thiếu

`(+)` S + must be + PII (by....)

`(-)` S + mustn't be + PII (by.....)

`(?)` Must + S + be + PII (by....)?

`2` You'd better put your money in the bank

`->` advise smb to V : Khuyên ai nên đó làm gì

`=` Smb had better + V : nên làm gì 

$@H$