Respostas
But (Mas) é uma conjunção adversativa, indicando oposição de idéias. Então após a afirmativa inicial nesses casos, convém uma negação, por isso o uso do Don't, ou Do Not.
I saw Simon last week but I DIDN’T SEE Tom.
They worked on Monday but they DON’T WORK on Friday.
We went to the post office last week but we DIDN’T GO to the bank.
He did his math homework but he DIDN’T DO his English homework.
She had a holiday last week but she DIDN’T HAVE one last month.
My mom bought new pair of shoes yesterday but she DIDN’T BUY any sandals.
Resposta:
a)I saw Simon last week but I DIDN’T SEE Tom.
b)They worked on Monday but they DON’T WORK on Friday.
c)We went to the post office last week but we DIDN’T GO to the bank.
d)He did his math homework but he DIDN’T DO his English homework.
e)She had a holiday last week but she DIDN’T HAVE one last month.
f)My mom bought new pair of shoes yesterday but she DIDN’T BUY any sandals.