Glossary · Word parts and vocabulary
What are free and bound morphemes?
Definition
A free morpheme can stand alone as a word, like help; a bound morpheme must attach to another part, like un- or -ful.
In helpful, help is free and -ful is bound. In unkind, kind is free and un- is bound. All prefixes and suffixes are bound by definition.
Many Latin roots are bound too. Rupt (break) never appears alone, only in words like erupt, disrupt and interrupt. Struct (build) is the same: structure, construct, instruct. Those bound roots are why upper-grade vocabulary seems so hard. Students can't look up rupt the way they look up help.
The distinction tells you what to teach first. Free bases with simple affixes come early, because students already know the base word. Bound roots come later, once students are used to looking inside words for meaning.
In a lesson
Sort helpful, disrupt, unkind and construct. The student underlines any part that could stand alone as a word. Help and kind can; rupt and struct can't.
Examples
Each word with its spelling units, one per sound.
- helpfulh·e·l·p·f·u·l
- disruptd·i·s·r·u·p·t
- unkindu·n·k·i·n·d
- constructc·o·n·s·t·r·u·c·t
Words come from our lexicon, checked against a pronouncing dictionary. Words a student sees in our assessments are left out.
Why does this matter for the record?
Rate free-base words and bound-root words separately. A student can be Secure on the first and still new to the second.
Rate each skill as you teach it
Needs support, Developing, Secure. The rating schedules the review and builds the report.