YOU SAID:

This day of substituting classes was really boring

INTO JAPANESE

この振替授業は本当に退屈だった

BACK INTO ENGLISH

This make-up class was really boring.

INTO JAPANESE

この補習授業は本当に退屈だった。

BACK INTO ENGLISH

This supplementary class was really boring.

INTO JAPANESE

この補習授業は本当に退屈でした。

BACK INTO ENGLISH

This supplementary class was really boring.