add prefixes and suffixes:

Statutory requirement

Pupils should be taught to add prefixes and suffixes:

• using the spelling rule for adding –s or –es as the plural marker for nouns and the third person singular marker for verbs
• using the prefix un–
• using –ing, –ed, –er and –est where no change is needed in the spelling of root wordsNon-statutory example: for example, helping, helped, helper, eating, quicker, quickest

Source: Department for Education, English programmes of study. See also the relevant statutory appendix. Crown copyright information reproduced under the Open Government Licence v3.0.