Basic English Syntax with Exercises

free morpheme

6.2 The syntax of inflection

When the inflection is represented by a free morpheme, such as a modal auxiliary or the infinitival to, nothing much happens to it. As a free morpheme it can stand by itself and hence we see it sitting in the head position:

6.2.3 Tense and Agreement

Before trying to solve these puzzles, one more mystery should be introduced. Our assumptions have been that auxiliaries are inserted into a structure to support bound morphemes when the verb is unable for one reason or another to do so. Obviously a free morpheme does not need supporting either by the verb or an auxiliary. This would predict that when the inflection appears as a free morpheme, i.e. a tense or the infinitival marker, there will be no need for an inserted auxiliary to accompany an aspectual morpheme. But this prediction seems to be false:

6.2.4 Movement to tense and I

Having separated tense and agreement (=inflection), let us consider their properties separately. Tense is obviously a bound morpheme triggering movement of the verb or insertion of an auxiliary when the verb is unable to move. But what about the null agreement morpheme, is this a bound morpheme or not? If it is, it will need supporting and we would expect verbs and auxiliaries to appear as high as the I node as we do not want to claim that the inflection lowers onto the tense. On the other hand, agreement might be like the modals and be a free morpheme, in which case we would expect nothing to move to I. The data are complex and often depend on other assumptions as to how to interpret them. Basically there appears to be a difference in how verbs and auxiliaries behave. Auxiliaries appear to be able to achieve a higher position than the main verb, indicating that while the verb can move to tense it cannot move to I, whereas auxiliaries can be in I.