Word Sums Worksheet Generator
A word sum writes a word as its parts: help + ful + ly → helpfully. This page makes sheets of them from 22 word families written for it — help, hope, happy, act, create, friend and others, 133 sums in all — asking pupils to build the word from its parts, split it into them, or both. Where the spelling changes at a join (hope + ing → hoping, happy + ness → happiness, run + er → runner), the answer sheet names the change.
What this generator does
Builds a sheet of different word sums from the families you draw, half to build and half to split in a mix, with an answer page that gives each sum, its word and the spelling change at the join, and lists the whole of each family used.
How to use this tool
- Choose build, split or a mix, and whether to focus on words with a spelling change.
- Set how many questions and how many word families to draw from.
- Press Make word sums, open an answer to check it, then print the sheet and its answers.
Understanding the controls
- Question type
- Build gives the parts and asks for the word; split gives the word and the number of parts; a mix alternates.
- Spelling changes
- Any word, only the 32 sums whose spelling changes at a join, or only the 101 that join unchanged.
- Questions and word families
- 1 to 24 different questions, drawn from 1 to 22 families; fewer families keep a sheet on a few bases.
- Hints, paper and seed
- Print the spelling-change hint beside each question if wanted; paper size; a seed rebuilds the same sheet.
Worked examples
- A mix, spelling changes only, 6 questions from 4 families, seed ‘spring’
- Families happy, like, move and use. Build happy + ness (happiness, y to i); split user (use + er, drop the e); build un + happy + ness; split liking; build happy + ly; split movable.
- How the 133 sums divide
- 101 join with no change and 32 change spelling: 19 drop an e (creativity drops two), 7 change y to i, 5 double a consonant and 1 turns -le into -ly (comfortably).
- A family as a graph
- act → action, active, actor, react; active → actively, activity, inactive; react → reaction; action → actions.
Common use cases
- A spelling lesson on adding suffixes
- Morphology practice: prefix, base and suffix
- A starter where pupils find the base before they spell the word
How this generator works
Each sum is stored as its parts and its finished word. The page rebuilds every word from its parts with four spelling rules and nothing else: drop a final silent e before a suffix starting with a vowel or y; change y after a consonant to i, except before i; double the last consonant of a one-syllable word ending in one vowel and one consonant (not w, x or y) before a vowel suffix; and turn -le into -ly. All 133 sums rebuild exactly. Every word also has a parent in its family — the same sum with its first or last part taken off — so each family grows one part at a time from its base.
Randomness and fairness
Families and questions are drawn with the browser's cryptographically secure generator, or from one seeded draw when a seed is typed. Seeded sheets are deterministic, not cryptographic. The words and their spellings are fixed data, not random.
For how randomness is produced across the whole site, see how Generate Random works.
Limitations and good to know
- The families were written for this page and checked by the rules above, not reviewed by a specialist; they keep to clear cases and leave out words with two accepted spellings (likeable or likable).
- Bases here are whole English words. Approaches that analyse bound bases and word origins (struct, rupt) need etymological sources this page does not use.
- The rules describe these words; English has exceptions (singeing, panicking) that the families deliberately avoid.
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