From Morris Halle, in response to Carstairs-McCarthy

[Alec Marantz]

Responding to Andrew Carstairs-McCarthy's comments on zero affixes:

A crucial aspect of the theory of DM has been the recognition that phonetic
zero must be included among the phonetic exponents of a morpheme.  To see
the necessity for this   consider the appearance of the helping verb in
yes-no questions such as those in (1).

(1)	John snore-[d, Past] 		di-[d, Past] John snore?
	John lef-[t, Past]		di-[d, Past] John leave?
	John sang-[zero, Past]		di-[d, Past] John sing?

It is generally recognized that the main verb is blocked from adjoining the
Tense morpheme in yes-no questions. Since the Tense morpheme is an affix and
must not remain stranded, the helping verb "do" is inserted. Like many other
grammatical formatives the Past tense has different phonetic exponents
depending on the verb to which the tense affix is adjoined. Specifically,
as illustrated in (1) English has three Past tense exponents: /d/ as in
snore-d, sol-d, di-d;  /t/ as in bough-t, los-t, knel-t, and zero as in
sang-0, burst-0, beat-0,  and the choice among them is determined -- as is
perfectly normal -- by the verb to which the affix attaches.

Equally typical is the fact that several distinct morphemes have the same
phonetic exponent.  For example, in English /s/ is the exponent of 3SgPres
of verbs, and of the Plural and Possessive of nouns.  The same is true of
zero.  In addition to being the exponent of the Past, zero is also the
exponent of the Perfect Participle of some verbs, and of the Present tense
(for Persons other than 3Sg) of all verbs.  In the latter case the reality
of the zero suffix is vouchsafed by the facts in (2), which precisely
parallel (1).

(2)	they snore-[zero, 3PlPres]	do-[zero, 3PlPres] they snore?

The preceding facts settle the question of whether English has zero affixes
for they show that -- as C-McC demands -- "that zero affixes behave just
like overt affixes."  C-McC's further requirement that they do so also "in
respect to readjustment" is not met, for there is no more reason for this
requirement than there is for the requirement that affixes triggering
readjustment should share any other phonetic property.  Note, in particular,
where zero is the exponent of the Present tense as in (2) it triggers no
readjustment.  As Past exponent, zero sometimes causes phonetic
modifications in the stem to which it attaches, sometimes not.  In this
again zeros parallel other Past tense exponents.  A few examples are cited in
(3).

(3)	Zero-Past with modifications:  sang-0,  struck-0, dug-o
	/t/-Past with modifications: knel-t, lef-t, bough-t
	/d/-Past with modifications: sol-d, tol-d  di-d, ha-d

	Zero-Past without modifications: beat-0, shed-0, cast-0, burst-0,
hurt-0,
rid-0, spread-0
	/t/-Past without modifications: burn-t, learn-t, dwel-t, knel-t
        <shortening here is due to a phonological rule, cf., Myers 1985 ,
CLS 21, 275-288>
	/d/-Past without modifications: seat-ed, bread-ed, putt-ed,
blast-ed, thirst-ed

Since /d/ is the default suffix, it is perhaps to be expected that it would
trigger stem modification only exceptionally.  C-McC is mistaken in
believing that there is a difference between /t/ and zero as to the extent
to which they cause stem modification. The fact that there are fewer
varieties of modification with /t/ than with zero is a result of the
different number of stems that take the respective suffixes.  There are
about 40 stems that take /t/, and about 130 that take zero. (Details in
Bloch, 1947, Language 23, 399-418.)  Nor should it be overlooked that the
zero exponent of the Present tense illustrated in (2) induces no stem
modifications whatever. These facts support the DM proposition that the stem
modifications are independent of the phonetic character of the suffix.
(Incidentally, the zero plural suffix as in fish, quail, deer, moose, etc.
appears without stem modification in the preceding, but triggers
modifications in geese, mice, lice, men, women.)

marantz at mit.edu