Language 5

Inflectional morphology

changes to a word that do NOT alter its underlying meaning (kiss → kissed)

Derivational morphology

changes to a word that alter its underlying meaning (develop → redevelop)

Regular verbs

verbs that signify past tense by adding -ed to the end (pinned, jumped)

Irregular verbs

verbs that do not follow the -ed rule for past tense (ran, slept, etc.)

Stage One of past-tense acquisition

Children start to use a small number of high frequency verbs in the past tense

Stage Two of past-tense acquisition

Children use more verbs that have a regular past tense

Overgeneralization of past-tense

Children apply regular past tense endings to irregular verbs; include verbs used correctly in Stage 1

Stage Three of past-tense acquisition

Children regain the use of the correct irregular forms of the past tense