Which prefixes should a 2nd grader know?

Un-, re-, dis-, mis-, and pre- cover most of what 2nd graders meet: unhappy, reread, disagree, misplace, preheat. Each has one plain meaning, and once a child knows un- means not, they can decode dozens of new words without help.

How do I explain what a prefix does?

Call it a meaning changer glued to the front. Lock is something you do with a key; unlock is the reverse; relock means do it again. The base word never changes its spelling, which is why prefixes are such dependable clues.

2nd grade prefixes

2nd grade prefixes worksheets

A prefix is a word part attached to the front of a base word that changes what it means. Second graders work with the heavy hitters: un- (not), re- (again), dis- (opposite of), mis- (wrongly), and pre- (before).

Free printable PDF worksheet, aligned to Common Core L.2.4.b.

Each print is a different sheet with its own answer key. You don't need to sign up.

The kind of sentences you'll get

Circle the letter of the word with the correct prefix.

The seatbelt sign means do not yet. misbuckle · rebuckle · unbuckle
Answer: unbuckle
Workers will the bridge after the flood. rebuild · unbuild · disbuild
Please the faded fence this spring. repaint · mispaint · unpaint

Every print pulls a new set of sentences at this level, so a make-up test or a second sibling gets a different mix.

What's on a 2nd grade sheet

2nd grade sheets draw from 60 sentences, 8 to a page. All 60 are on 3rd grade sheets too, along with 60 more. 3rd grade sheets print 10 to a page.

Some of the answers:

unlockuntiereturnrestartretakedislikepreheatuncertainunluckyunwelcome

Choose the word. Circle the letter of the word with the correct prefix. 8 questions per page.

Every version prints on US Letter or A4, with its answer key on the last page.

How to teach this

Teach each prefix as a tiny machine with one job: un- flips things off or backward, re- runs them again. Build words physically with two cards (un + lock) and slide them together. When your child meets a wrong option like "relock the door I can't open," ask what the sentence wants the word to do.

Watch for: A prefix changes meaning, not spelling: the base word keeps all its letters (re + read = reread). Not every word that starts with those letters has a prefix. Uncle isn't un + cle.

Common questions about 2nd grade prefixes

Which prefixes should a 2nd grader know?: Un-, re-, dis-, mis-, and pre- cover most of what 2nd graders meet: unhappy, reread, disagree, misplace, preheat. Each has one plain meaning, and once a child knows un- means not, they can decode dozens of new words without help.
How do I explain what a prefix does?: Call it a meaning changer glued to the front. Lock is something you do with a key; unlock is the reverse; relock means do it again. The base word never changes its spelling, which is why prefixes are such dependable clues.

Related worksheets

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Aligned to Common Core L.2.4.b. Reviewed by the One more sheet team. Content version 241, updated October 2026.

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