Corroborate, Refute, and Undermine

Recognize verbs that describe how evidence supports or weakens a claim.

Analytical writing constantly describes what evidence does to a claim. Corroborate means to confirm or support with additional evidence; from Latin corroborare, 'to strengthen,' related to robur, 'strength. ' Refute means to prove a claim false with evidence or argument. Undermine means to weaken a claim, often gradually or indirectly, without fully disproving it. The difference between refute and undermine matters: refuting is decisive, undermining is partial. Worked example: a witness says she saw the suspect downtown at noon.

A security video showing him downtown at noon corroborates her account. A receipt proving he was in another city at noon refutes it. Learning that the witness was not wearing her glasses undermines her account; it may still be true, but we trust it less. On tests and in essays, choose the verb that matches the strength of the evidence.

• 1Corroborate: support with additional evidence.
• 2Refute: prove false.
• 3Undermine: weaken without fully disproving.