Formally-Formerly | Commonly Confused Words

Formally

/ˈfɔːməli/

In a manner that follows formal rules or customs

He was formally invited to join the board.The law was formally approved last week.She was formally dressed for the gala evening.

/ˈfɔːməli/

Previously known by a different name or in a different state.

'Then it IS the lady as formerly objected?' said Wegg.I was a countryman formerly.""One of the four braves who formerly performed such prodigies."

Formally refers to things done in an official or proper manner.
Formerly indicates something that occurred in the past.
Remember formal is related to formal attire or formal events, which are proper and official.
Formerly contains form but deals with things that once existed but not anymore.
Formally also contains the word formal, hinting at manner, while formerly shares its root with former, suggesting past events.