“Do you swear to tell the truth, the whole truth, and nothing but the truth?” This is the expectation for testifying in court: that you tell the truth without embellishment or omission. Failure to tell the truth in court is perjury, a punishable offense. There is an exception, however. You can plead the Fifth Amendment to the US Constitution, which states that you shall not be compelled in any criminal case to witness against yourself.
