YOU SAID:

today's class is annoying becuase I have to pay attention

INTO JAPANESE

今日のクラスは私が注意を払わなければならないので迷惑な

BACK INTO ENGLISH

Today's classes are annoying as I have to pay attention

INTO JAPANESE

私は注意を払わなければならないとして今日の授業は迷惑です

BACK INTO ENGLISH

Today's lesson is annoying as I have to pay attention

INTO JAPANESE

今日のレッスンは私が注意を払わなければならないので迷惑です

BACK INTO ENGLISH

Today's lesson is annoying as I have to pay attention