Exercício: Correção de frase em inglês

"I'm sure they didn't took English in high school."

Boa dia/tarde/noite!
Gostaria de saber o item incorreto da frase.
Valeu!
MENSAGEM PATROCINADA Faça um teste de inglês e descubra seu nível em 15 minutos! Este teste foi desenvolvido por professores e linguistas certificados. O resultado sai na hora e com gabarito.

Clique aqui para iniciar o Teste Online!
Avatar do usuário Joarez.GN 885 3 13
A frase correta seria,

"I'm sure (that) they didn't take English classes in high school."

Cheers!
Avatar do usuário PPAULO 39205 6 32 684
And that´s why:

With a negative sentence in which you use "did not/didn´t" it means that the (main) verb doesn´t conjugate as we learn in basic English (when we learn verb to be/to have, for example). The verb don´t go the past form.
The "did not/didn´t" simply "kills" the conjugation, and then the verb works in its infinitive form (present infinitive form, some people would say).

Say, by way of examples: take continues as take/work as work/give as give. And so on...

Back to your initial sentence then:
"I'm sure they didn't took English in high school." The verb is not correctly used, it should be "I'm sure they didn't take English in high school."