Definition

To find out something for sure, often by checking or investigating.

Example

The detective worked hard to ascertain the truth behind the mystery.

Tense Forms

Conversation

Hey, did you manage to ascertain the meeting time for tomorrow?

Not yet, I was just about to check my emails for that.

Let me know once you ascertain it, so I can plan my day.

Of course! I’ll text you as soon as I find out.

Synonyms & Antonyms

Root Explanation

Ascertain is formed from "ad-" (meaning to) and "certus" (meaning sure or certain). The word means to make sure of something or to find out with certainty.

Memory Tip

Think of 'to' ('ad-') make something 'certain' ('certus') — that's how ascertain means to find out something with certainty.

Visually Confused Words