Collocations for swear - verb

loudly
quietly, silently, softly, under your breath
viciously, violently

hear sb
He heard her swear under her breath.

at
He swore loudly at her and left.

solemnly
He swore solemnly that he would never hit her again.

on oath, under oath
up and down (AmE)
He swears up and down that he trusts me.

be prepared to
I would be prepared to swear on oath that they didn't see me.

make sb
He made her swear on the Bible that she wouldn't leave him.

by
I swear by Almighty God to tell the truth.

on
Do you swear on your mother's life?

to
I swear to you, I don't know.

be sworn into office
Lincoln was sworn into office on March 4, 1861.

swear sb to secrecy, swear sb to silence
We were all sworn to secrecy about the plan.

Swear is used with these nouns as the object:
allegiance, loyalty, oath, vengeance