YOU SAID:

Being an adult is hard.

INTO JAPANESE

大人であることは難しいです。

BACK INTO ENGLISH

In adults it is difficult.

INTO JAPANESE

成人では困難です。

BACK INTO ENGLISH

In adults is difficult.

INTO JAPANESE

大人には難しいです。

BACK INTO ENGLISH

It is difficult for adults.

INTO JAPANESE

大人は困難です。

BACK INTO ENGLISH

Adults is difficult.

INTO JAPANESE

大人は難しいです。

BACK INTO ENGLISH

Adults is difficult.