YOU SAID:

now that i have to think of one i cannot.

INTO JAPANESE

今私は私ができないものを考える必要があります。

BACK INTO ENGLISH

Now I need to think what I can not do.

INTO JAPANESE

今、私はできないことを考える必要があります。

BACK INTO ENGLISH

Now, I need to think about what I can not do.

INTO JAPANESE

今、私はできないことについて考える必要があります。

BACK INTO ENGLISH

Now, I need to think about what I can not do.