YOU SAID:

There were many tomatoes that were lemons really

INTO JAPANESE

本当にレモンであるトマトがたくさんありました

BACK INTO ENGLISH

There were a lot of tomatoes that were really lemons

INTO JAPANESE

本当にレモンだったトマトがたくさんありました

BACK INTO ENGLISH

There were a lot of tomatoes that were really lemons