Extant is an adjective meaning still in existence, and extent is a noun meaning the area, range or degree of something. Remember that extant ends in -ant like a plant that is still alive, while extent is the size of something, as in the full extent of the damage.
The core difference
Extant describes something that still exists, whereas extent names how far, wide or great something is.
- extant — still in existence: Only three copies of the manuscript are extant.
- extent — the area, range or degree of something: We don't yet know the full extent of the damage.
How to tell them apart
Ask what job the word does. If it describes a thing that has survived, you want the adjective extant, the opposite of extinct or lost. If it names how far or how much, you want the noun extent, as in to what extent do you agree.
The mix-up appears because the words share most of their letters and are pronounced in a similar way. Extant comes from a Latin verb meaning to stand out or exist, while extent is linked to a word meaning to stretch out, which is a handy way to keep the second one about size and range.
