YOU SAID:

I'm not very sure that I'm able to do that

INTO JAPANESE

私はそれができるかどうかよくわかりません

BACK INTO ENGLISH

i'm not sure if i can do that

INTO JAPANESE

それができるかどうかわからない

BACK INTO ENGLISH

i don't know if i can do it

INTO JAPANESE

できるかどうかわからない

BACK INTO ENGLISH

i don't know if i can

INTO JAPANESE

できるかどうかわからない

BACK INTO ENGLISH

i don't know if i can