The dog is touched by the cat

Morphology

The rules combining words or parts of words into new words (e.g. adding -ed onto jump to make the past tense form jump-ed; adding self onto him to form the pronoun himself). Children with a language impairment may have problems with morphology and therefore do not add endings or beginnings to the "core" of words.

For example, they may produce a sentence such as "Yesterday, I walk". (The correct sentence would be "Yesterday, I walked".)

Young children by the age of 5 years or younger are usually good at marking a verb as being in the past tense or using other grammatical morphemes (e.g., -ing, -s). However, a child with language impairment may continue making such errors past the age of 6 years old.

Children also need to learn to use regular and irregular verbs morphology correctly. For example, to mark tense of regular verbs we add -ed (jump-ed), but to mark tense on irregular verbs we use a different form of the verb. For example the past tense of fall is fell (not falled), the past tense of go is went (not go-ed).

Children with language impairments frequently have problems using regular verb morphology, which typically developing children find easy, and also often do not mark the past tense on either regular and irregular verbs.