Learning to eat in the past

How do young children learn to create inflected forms of words? For example, how do they learn that:

• most English verbs form the past tense with the suffix -ed (eg walked from walk);
• some English verbs undergo other types of change in the past tense (eg sat from sit);
• a few have complexly unrelated past tense forms (eg went from go)?

Stages in learning past tense

Children start by learning individual forms, such as walked, sat or went. Later, they begin to realise that there are underlying rules (such as adding the suffix -ed to walk to form the past tense form walked). At that stage, they still separately in their memories forms (such as sat or went) that the -ed rule doesn’t fit. After a while, many children go through a phase where they overextend the rule, applying it to verbs that adult English speakers don’t apply it to. For example, they might produce forms such as sitted or goed (instead of sat or went). Ultimately, they settle down to using the adult forms in all cases.

Past tense of the verb ‘eat’

I heard an example of this overextension recently from my oldest grandchild, when he was 6 years, 9 months. He said he ‘ated’ something, using ‘ated’ as the past tense of the verb eat. His use of the form ‘ated’ struck me for 3 reasons:

• He is clearly overextending the normal -ed past tense rule, applying it to a strong verb that doesn’t take the -ed ending in standard southern British English. I don’t know whether he is just doing this for the verb eat or whether it is a more general process. At any rate, I don’t recollect hearing him do this for any other verbs recently. And I’ve heard him say ‘ated’ before, so it doesn’t seem to be an isolated occurrence.
• It isn’t just a straight over-extension, though. He is applying the suffix -ed not to the present tense stem eat but to the past tense stem, as if it were a ‘strong’ verb, such as tell (with both a change of vowel and an -ed suffix in the past: told)
• He may also be unsure what vowel to use in this case, perhaps because of something specific to this particular verb. As a child, I often hesitated between standard [eɪt] (sounding like the number eight), which my mother used, and [ɛt] (with the vowel as in get), which my father used.
  I think I now always use the standard [eɪt]. I suspect this is partly because of influence from the spelling, partly from school and partly because this is now virtually the only form I hear from almost everyone around me these days.

Past participle

My grandson also uses ‘aten’ as the past participle of the verb eat. So do his brother (4 years, 6 months) and cousin (4 years, 3 months). Their form ‘aten’ differs from the standard ‘eaten’ only by a difference in vowel.

In contrast, his form ‘ated’ differs from the standard form ‘ate’ in a more complex way: by supplementing the same changed vowel with the regular suffix -ed. Thus, his form ‘ated’ marks the past tense with a combination of 2 changes: changing the vowel and adding the regular suffix -ed.