It has come to my attention that the term “inflected” may not be familiar to some of you, so let me just outline what “inflected” is supposed to refer to.

The term “inflected” here means basically “with a tense/agreement ending.” Adults use inflected verbs generally, except in the infinitive (where there is no tense or agreement—that’s basically what “infinitive” is supposed to indicate). So, agreement refers to subject agreement, the ending on the verb that goes with the person/number/gender of the subject. In English, these endings are not very elaborate—almost all agreement endings in English are silent (which is written as -∅, “zero”, no pronunciation). (Other languages often have more tense/agreement morphology on the verbs.)

• I go
• we go
• you go
• they go
• he goes
• she goes
• it goes

It is only with third person singular subjects that you see a mark on the verb indicating agreement with the subject: That is the “-s”. So, it is really only those verbs with a visible ending that we could certainly class as inflected.

An uninflected form, then, is one that is missing the ending—and in the experiment outlined in the homework, errors arising from using a verb that should have had an ending but from which the ending is missing are only going to be detectible with a third person singular subject. That would be something like:

• he go
• she go
• it go

Those would count as uninflected forms.

(As an aside, things are a little bit special with the verb be—be shows a little bit more elaborate agreement. With be there are special inflections for first person (“I am”) and third person (“he is”), but 2nd person (you) and all plurals come out the same way (“are”). The uninflected form is “be”.)

All of the examples above are in the present tense. In English it turns out that the only time you can see any subject agreement is in the present tense (except with be—and in the past tense with be you only see number agreement—”was” for singular [except for second person], and “were” for everything else—all plurals and all second persons).

• I went
• you went
• he went
• they went

The tense marking also counts as inflection, so all of the past tense examples above count as inflected as well. The uninflected form is still “go” or “be”.

The last question of the homework refers to a table concerning child utterances containing not, and gives the table in the same form as the others, crossing inflection in the stimulus with inflection in the child’s utterance.

“But wait,” you might say, “you don’t get inflected verbs with not in English. What’s going on?”

Indeed, a verb negated with not in English is not inflected, the inflection is carried on do: He does not go. The trick here is revealed by looking at (8b), which is the stimulus sentence for the inflected-not condition. What the researchers did is put the not in a higher clause: Do you think that he goes, or don’t you think that he goes? So, goes is inflected in the stimulus sentence, as advertised, and children (like adults) interpret this as meaning the same thing as Do you think that he goes, or do you think that he doesn’t go?—and, it seems, answer accordingly.