Basic English Grammar with Exercises

Chapter 6 - Inflectional Phrases

2.1 Inserting auxiliaries into I

In the previous chapter, we introduced the idea that dummy auxiliaries are inserted
into a structure when the verb is unable to support a bound morpheme. Consider what
happens with regard to a bound inflectional element such as the present tense
morpheme s:

(19) a IP b IP

• I' – I'

I vP I vP

-s v' -s v'

v VP v VP

-en DP V' -ing DP V'

he V she V PP

arrive live in London

‘he has arrived’ ‘she is living in London’

In both of these examples, the verb moves from the V position to support the aspectual
morphemes. As a consequence of English stems being unable to support more than one
overt morpheme, the verb cannot move further. As the inflection is a bound morpheme
it needs supporting and in this case the auxiliaries are inserted directly into the
inflectional slot. Note that which auxiliary is used depends on the aspectual element
heading the vP complement of the inflectional element. A perfective aspectual
morpheme determines the supporting auxiliary to be have while the progressive
morpheme determines the supporting auxiliary to be be. With a slightly more complex
example, we see that this is a very general process:

have

be