Recent years have seen a number of attempts to analyze phenomena that have been regarded as agreement in different terms. For instance, many cases of purported object agreement have been argued to be clitic doubling (Preminger 2009; Nevins 2011; Kramer 2014). In a recent paper, Weisser (2019) proposes to reanalyze the Breton rannig, Busan Korean complementizer alternations, and complementizer agreement in West-Germanic as allomorphy. In addition, based on his reanalysis of these phenomena, he proposes a set of diagnostics to distinguish agreement from allomorphy. In this squib, I show that while Weisser’s reanalyses of the Breton rannig and the Busan Korean complementizer alternation in terms of allomorphy are convincing, West-Germanic complementizer agreement differs from these phenomena in several ways, which forces Weisser to weaken his proposed diagnostics. I will present novel and little discussed data on complementizer agreement that is not amenable to an analysis in terms of allomorphy, or in fact any PF account of complementizer agreement. Accepting that complementizer agreement is not allomorphy allows us to formulate a stricter set of diagnostics to distinguish allomorphy from agreement. More generally, this squib contributes to the long-standing debate on the status of complementizer agreement as Agreement (Carstens 2003; van Koppen 2005) or resulting from a PF operation (Ackema & Neeleman 2004; Zwart 2006; Fuß 2014) (see van Koppen 2017 for a recent overview), explicitly arguing against the latter approach.

In this section, I present three data points on CA that are problematic for an allomorphy account.2 The aim is to show that we should not regard CA as allomorphy. All data in this section come from my own elicitations with native speakers.

The first points come from Frisian. Without disrupting the linear adjacency between the complementizer and the subject, Frisian CA looks similar to Bavarian CA. However, the effect of intervention is quite different: in Frisian, disrupting the adjacency relation between the complementizer and the subject leads to ungrammaticality with and without the CA morpheme on C (9) (see de Haan 2010 for comparable data).

Note that it is not ungrammatical per se to disrupt the relation between the complementizer and the subject in Frisian, cf. (10).

Furthermore, the ungrammaticality of (9b, 9c) cannot be due to a problem with modifying a 2SG pronoun specifically. Frisian allows for V2 embeddings, which never have CA. In a V2 embedded clause with a 2SG subject, it is fine to modify the subject with a focus particle:

Thus, the ungrammaticality of (9b, 9c) seems to be crucially connected to the presence of CA in the non-modified counterpart (9a). As such, it is inexplicable under any PF account of CA. Under standard assumptions, whether a sentence is grammatical or not is determined in the syntactic part of the derivation. All that PF can do when the derivation is sent there is make alternations to the phonological shape of the utterance, which should not affect grammaticality. Since in (9b, 9c) the ungrammaticality is related to CA, and PF alternations do not affect grammaticality, we must conclude that CA is not created in the PF component of the derivation. This provides strong evidence against a PF account of CA.

The second point from Frisian is based on first conjunct agreement. While CA is obligatory with simple subjects, it is optional with coordinated subjects where the first conjunct is a 2SG pronoun. Having or not having first conjunct CA has effects on interpretation. See (12) for examples.34

The first conjunct CA data are problematic in two ways. First, I see no way to posit a CA rule based on linear adjacency that captures the optionality when the subject is part of a coordinated subject and the obligatoriness when it is not. Second, more pressingly, first conjunct CA can only have an interpretative effect if the structural configuration that establishes it is already present in syntax. A PF rule, such as allomorphy, should not be able to affect semantics in this way.

The third, slightly more intricate point comes from novel data from Southern Limburgian.5 Without disrupting the adjacency between the complementizer and the subject, Southern Limburgian is very similar to both Bavarian and Frisian. The intervention effect in Southern Limburgian is yet different, however: when an element intervenes between the complementizer and the subject, the CA morpheme appears directly to the left of the subject, cf. (13). The size of the intervening material does not matter; in (13c), a topicalized direct object and a focus particle attached to the subject intervene between the complementizer and the subject.

Thus, like Bavarian, the Southern Limburgian data illustrate a non-local alternation. However, in contrast to Bavarian, for which Weisser (2019) argued that CA depends on a relation between the agreement head and T, the Southern Limburgian data shows that CA must depend on a relation between (at least) the complementizer and the subject, as in this case it looks like the subject is the alternant, and not the complementizer. Since the complementizer and the subject are both structurally (13c) and linearly (13b, 13c) non-local, this cannot be modelled in an allomorphy account that relies on (structural or linear) adjacency.6

Summarizing this section, I have presented new data points on CA that are not compatible with PF approaches to CA, such as allomorphy. I conclude that CA is not created in the PF part of the derivation. As we will see in the next section, this actually has some welcome consequences for Weisser (2019)’s diagnostics to distinguish agreement from allomorphy.

Based on the conclusion that CA is not allomorphy, I propose to revise some of the allomorphy diagnostics proposed by Weisser (2019), repeated in (14).

The first revision I propose has to with adjacency, and indirectly with the trigger for allomorphy (diagnostics (14a) and (14b)). The analysis of CA as allomorphy forces Weisser to assume that allomorphy can also apply under structural adjacency. Eliminating CA as allomorphy therefore allows us to discard this assumption and maintain a very strict locality condition on allomorphy: allomorphy is always triggered by the features of an element that is linearly adjacent to the alternating morpheme. In other words, we can formulate a stronger diagnostic than the initial proposal, which was unable to identify cases of non-local alternations as agreement or allomorphy; according to the revised diagnostic, non-local alternations cannot be allomorphy. If we accept the linear adjacency condition on allomorphy, we can also restrict the trigger of allomorphy: allomorphy only scans a linear local domain for a trigger, not a structural local domain. This has the additional benefit that structure does not have to be transferred to PF.

The second revision that I propose has to do with diagnostic (14d), which states that if an alternation is sensitive to non-canonical agreement features, we are dealing with allomorphy. CA refrained us from saying anything about cases in which canonical agreement features trigger an alternation, since it is triggered by canonical agreement features, but still regarded by Weisser as allomorpy. Given the conclusion that CA is not allomorphy, we can make a stronger claim, namely that alternations triggered by canonical agreement features are not allomorphy. While in order to test this claim it is necessary to look at morpheme alternations in a large number of languages, which is obviously beyond the scope of this squib, I would still like to point out the conceptual appeal of this diagnostic, since it would prevent us from positing different mechanisms (agreement and allomorphy) in different domains (syntax and PF) that lead to highly similar outcomes. For this reason, I include it nevertheless.

The revised diagnostics are summarized in (15). The overall consequence of the revision is that allomorphy and agreement are regarded as completely non-intersective processes, operating in distinct parts of the grammar under distinct constraints. As such, the revisions reinforce Weisser’s point that there are multiple types of word-external dependencies in the grammar, which should be distinguished empirically and analytically.

In this squib, I discussed the three cases of purported agreement that Weisser (2019) argues should be analyzed as allomorphy. While for the Breton rannig and the Busan Korean complementizer alternations, the argument is well-grounded and the results coherent, we have seen that West-Germanic CA patterns differently in some respects. In addition, I have given three more data points that are problematic for an allomorphy account of CA (and in fact any PF account of CA), based on novel and underdiscussed data. I concluded that CA is not a PF phenomenon. As it turns out, this is a welcome result, since eliminating CA as allomorphy allows us to maintain a stricter set of diagnostics for distinguishing allomorphy from agreement than Weisser’s initial proposal.