Unit 23 - Prefixes

You will remember from Unit 9 that there are many different rules for adding a suffix to the end of a root word:

Double a letter?
Drop a letter?
Change a letter?

What about adding a prefix?

prefixes pre anti un tele dis in mis sub

English spelling prefix The good news is: the root words never change when you add a prefix. Sometimes you will have double letters but this is because the prefix ends with the same letter as the start of the root word, for example:
dissolve unnecessary innovation misspell

Teaching point - learning to spell Sometimes the prefix needs to change. The words all and well drop one letter l when they are used as a prefix:

well + come = welcome well + fare = welfare
all + ways = always all + so = also all +most = almost
all + though = although all + mighty = almighty

Note: alright or all right?
It is possible to use one word: alright. However, it is better English to use two words: all right.

English spelling prefixes More good news! Some other prefixes do change - but the good news is:
It has already been done for you, in the way the English language has changed over hundreds of years. Look at how the prefix in is used to make these words mean the opposite:
in + capable = incapable in + correct = incorrect in + curable = incurable

Teaching point - learning to spell The prefix in means 'not'. Suppose you wanted to say something was 'not regular'. It would be hard to say 'in-regular', so the prefix has changed to match the root word and we say 'irregular'. The same thing happens with m and l , for example:
in + mobile = immobile in + literate = illiterate

Use im before words that start with p:   in + proper = improper

Try this final test. Add another letter to complete each word.

English spelling learning tip Listening to the sound of the prefix will help you decide which letter to use.

Work out which letters are missing then type the whole word.

An i___logical explanation.
An i___frequent bus service.
An i___passable road.
An i___moral person.
An i___accurate figure.
An i___possible puzzle.
An i___resistible dessert.
An i___legal drug.
An i___dependent woman.
An i___polite child.
An i___responsible action.
An i___mature teenager.


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Unit 23: Prefixes

Page 8 of 9

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