YOU SAID:

Much has changed while I was away.

INTO JAPANESE

私が留守の間に多くが変わった。

BACK INTO ENGLISH

Many things changed while I was away.

INTO JAPANESE

私が留守の間に多くのことが変わった。

BACK INTO ENGLISH

A lot has changed in my absence.

INTO JAPANESE

私がいない間に多くのことが変わった。

BACK INTO ENGLISH

A lot has changed in my absence.