Formally vs Formerly: Officially or Previously?

Formally comes from formal; formerly comes from former. One concerns manner or official status, the other earlier time.

The agreement was formally approved. / The building was formerly a library.

Use the base word to check yourself

If you can paraphrase with officially, choose formally. If you mean previously, choose formerly.

Word-family awareness prevents many spelling confusions; review word families. When formal refers to register, compare email tone and register.

Register versus chronology

Formally can also describe style: She was dressed formally. Formerly always points backward in time: The company, formerly known as…. In editing, replace the word with officially/formal in manner or previously; the correct choice becomes obvious.