Patterns of agreement with `polite' second person forms vary across languages. Mixed Agreement is found in French, Rumanian, Czech, and Bulgarian. For example, with French vous} (plural or formal `you'), the finite V is plural while the predicate adjective number reflects semantics:
| Vous | etes | loyal. |
| you.pl | be.2.pl | loyal.m.sg |
| `You (one formal male addressee) are loyal.' | ||
| Vous | etes | loyaux. |
| you.pl/formal | be.2pl | loyal.pl |
| `You (addressee + associate(s)) are loyal.' | ||
Uniform Agreement is found in Serbian/Croatian and Persian: the formal second person pronoun triggers plural agreement on all targets. Building on the treatment of French in Wechsler (2004), this paper explains this variation in terms of differing features of the pronouns. The main substantive premise is that singular number targets such as loyal are doubly marked for both morphosyntactic singular and singular (`non-aggregate') semantics. The plural form is the general form (unmarked, in the Jakobsonian sense), hence it has the elsewhere distribution, occurring when the singular cannot appear because the trigger is either [NUMBER PL] or has aggregate semantics. Mixed agreement arises when the pronoun (e.g. French vous) lacks a NUMBER feature altogether (finite verbs do not agree in number, but distinguish more PERSON values than traditionally assumed). Uniform agreement arises when the pronoun is marked for NUMBER. This proposal relativizes Cysouw's (2003) contention that first and second person pronouns lack a number feature, suggesting that languages vary in this regard.