The phrase "used to be" is a common part of our daily conversations. It indicates that something existed or happened in the past that is no longer true or relevant. There are several synonyms for this phrase, such as "formerly," "once," "previously," "before," "back then," "in the past," "in former times," "in earlier days," and "at one time." Each of these words or phrases can be used to convey the same meaning as "used to be" and may change the tone or nuance of a sentence. So, choose your words carefully to make an impact and express your thoughts clearly.