Basic English Syntax with Exercises

zero inflectional morpheme

6.2.3 Tense and Agreement

These observations show that this zero morpheme is in complementary distribution with tense and thus the straightforward conclusion is that it IS tense. But how can this be if tense is an inflectional element and the zero morpheme is not in complementary distribution with modal auxiliaries, which are also inflectional elements? What the data show is that it is not modals that tense is in complementary distribution with, but the zero tense morpheme that accompanies the modal and hence the conclusion is that if modals are of the category ‘inflection’, then tense is not of this category. Given that tense is situated in front of the VP, we can assume that it is a head that selects a verbal complement and given that it follows the inflectional elements (i.e. modals) it must project a verbal phrase. In other words, tense is yet another light verb:

6.2.3 Tense and Agreement

The inflectional head has a very important role in determining the nature of the following tense head. As we have seen, modals determine that tense will appear as a null morpheme, but note that its content, i.e. past or present, can be recovered from the modal itself, which inflects for tense. When the inflectional element is a null agreement morpheme, the form of the tense will be partly determined by the agreement morpheme and partly by the tense itself. So if the tense is past then it will be realised as ed (or one of its irregular forms) no matter what the agreement is. But if the tense is present, it will be realised as s when the agreement is third person and singular and as a zero morpheme when the agreement is something else: