Typing the start of an operator suggests it, in a list rising from the word; right after one, the people from contacts (from:, to:, cc:), the labels (label:, in:), or the values (is:) it takes. A bare word is never completed, so a name typed alone stays a word to search. Tab or Enter takes a suggestion while the list shows, and an operator taken goes on to its values. Contacts now suggests anyone for no words, which compose never asks.