Second Grade · Reading · week 14

Prefix Un-: Not and Opposite

Read and understand words with the prefix un-, which means "not" or "the opposite of," added to the front of a base word.

A prefix is a word part added to the FRONT of a word that changes its meaning. Un- usually means "not." Happy becomes unhappy, which means not happy.

Sometimes un- means "do the opposite" instead, like unlock, which means do the opposite of lock -- open it. Either way, spot the base word first, then add un- to the front.

📋 For the teacher
Teach it (10–15 min):
  • Point out the base word first (happy, lock, fair), then add un- to the front.
  • Ask for the meaning of the new word every time, not just how to read it.
  • Notice the two jobs of un- together: "not" (unhappy) and "opposite action" (unlock) -- both are correct, so there is no need to stress over which one applies.
  • Have your child use a new un- word in a sentence of their own.
Talk about it:
  • What does the prefix un- usually mean?
  • Can you think of your own un- word?
  • What is the base word inside unsafe?

Mastery looks like: They read un- words fluently and correctly explain their meaning as "not" or "the opposite."

Common stumbles: Reading only the base word and forgetting to include the un- prefix, which changes the whole meaning.

See it visually

Interactive, spoken-aloud tools that show this idea in motion.

Prefixes & SuffixesAdd un-, re-, -ful, -less and watch a word’s meaning change.try →Synonyms & AntonymsSlide from cold to hot and explore shades of meaning.try →Greek & Latin RootsBuild big words from roots: photo + graph → photograph.try →
Homework for this lessonType it, write it with a stylus, or print it for pencil & paper.open →
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