YOU SAID:

I'm using my time wisely by doing nothing while on a lecture

INTO JAPANESE

私は講義中に何もせずに自分の時間を賢く使っています

BACK INTO ENGLISH

I use my time wisely without doing anything during the lecture

INTO JAPANESE

私は講義中に何もせずに自分の時間を賢く使う

BACK INTO ENGLISH

I use my time wisely without doing anything during the lecture