YOU SAID:

Guess I'd better get good.

INTO JAPANESE

元気になった方が良いと思います。

BACK INTO ENGLISH

I think you should get better.

INTO JAPANESE

もっと良くなるべきだと思います。

BACK INTO ENGLISH

I think it should be better.

INTO JAPANESE

もっと良いはずだと思います。

BACK INTO ENGLISH

I think it should be better.