
Word Builder
A root carries a word's core meaning; a prefix snaps onto the front and a suffix snaps onto the end to change or refine that meaning.

What your child will figure out
- Identify the root as the block that carries a built word's core meaning.
- Use prefixes for negation, repetition, position, time, number, and degree to change a root's meaning predictably.
- Use suffixes for qualities, states, people, actions, and possibility to change a root's meaning predictably.
- Build and break unfamiliar single- and multi-affix words across everyday, school, story, community, and science contexts.
The levels
- Find the power block
Predict, build, observe, and explain that the root help carries the core meaning.
- Flip it with un-
Build unkind and explain how a negating prefix changes kind to its opposite.
- Run it again
Build reuse and distinguish repetition from negation.
- Finish with -ful
Build helpful and explain how a quality suffix changes the root.
- Take it away
Build fearless and contrast -less with -ful.
- Look before
Build preview and use a time-and-order prefix in a school context.
- Spot the mistake
Build misread and explain that mis- marks an action done wrongly.
- Name the doer
Build teacher and explain how -er can name a person who acts.
- Turn quality into an idea
Build kindness and explain how -ness names a state or quality.
- Show possibility
Build washable and explain how -able marks what can be done.
- Build by number
Build semicircle and use a quantity prefix in a maths context.
- Master blueprint
Transfer the full block rule by building unpredictable with both a prefix and suffix.
Ready when they are.
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Play Word Builder free