General:
* Vow: This emphasizes a promise or commitment.
* Declare: This suggests a formal statement.
* Assert: This implies confidence and conviction.
* Promise: This specifically refers to a commitment to do something.
* Affirm: This suggests a strong confirmation or agreement.
Informal:
* Curse: This implies anger or frustration.
* Damn: This is a stronger, more informal version of "curse."
* Blast: This is a slang term for "curse."
* Cuss: This is a more common, informal synonym for "curse."
Legal:
* Testify: This refers to giving evidence in a legal proceeding.
* Depose: This is a formal synonym for "testify."
* Affidavit: This is a written statement made under oath.
To understand the best synonym for "swear," you need to consider the context of the sentence.