Which spelling rules does it use?

The four a primary scheme teaches: just add it, drop the e before a vowel suffix, double the last letter after a single short vowel, and change the y to an i unless the ending starts with i.

Why is forgetting not in it?

Because it doubles for a reason the four rules do not cover: the stress falls on the last syllable. Words like that are left out rather than handled as exceptions, so everything on the board can be explained by a rule the class has been taught.

Do prefixes change the spelling?

No, and that is the point of having them here. The root word stays exactly as it is, which is why we write misspell with two s's and unnecessary with two n's.

Prefixes and Suffixes

English · Year 2–Year 5

Add an affix, and see what happens to the spelling.

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About the prefixes

A root word on the board and the affixes on the toolbar. Tap -ing or -ed or un- and the board shows what happens: the sum with the letter the rule takes off struck through, the finished word with the letter it brings in marked, and the rule itself written out underneath.

The spelling change is the objective. Sticking -ing on the end of a word is not what a class gets wrong; knowing that hope becomes hoping and hop becomes hopping is, so both words are in the bank, and so are carrying against carried and hoping against hopeful.

It works the spelling out from the four rules a primary scheme teaches: just add it, drop the e, double the last letter, and change the y to an i. What those rules do not cover is left out of the word bank rather than special-cased, because a class cannot apply a rule they have not been told, and a tool with a quiet fifth rule in it is worse than a shorter list. Every word in the bank is also authored with the answer, and a test holds the two against each other: a wrong spelling would fail the build rather than reach a board.

A prefix never changes the root word, which is the whole lesson rather than a simplification. It is why misspell has two s's and unnecessary has two n's, and both of those are in here.

An affix a word does not take is greyed out, so nothing on the toolbar can spell a word that is not a word.

How to use it on your whiteboard

1Read the root word, and ask the class what will happen to the spelling.
2Tap a suffix to add it. The board shows the join and names the rule.
3Tap a prefix as well for words like unhappily.
4Tap the same affix again to take it off, or Clear for both.
5Tap Next for the next word.

Questions

Which spelling rules does it use?: The four a primary scheme teaches: just add it, drop the e before a vowel suffix, double the last letter after a single short vowel, and change the y to an i unless the ending starts with i.
Why is forgetting not in it?: Because it doubles for a reason the four rules do not cover: the stress falls on the last syllable. Words like that are left out rather than handled as exceptions, so everything on the board can be explained by a rule the class has been taught.
Do prefixes change the spelling?: No, and that is the point of having them here. The root word stays exactly as it is, which is why we write misspell with two s's and unnecessary with two n's.