Does Agreement Have A Prefix Or Suffix

[2] [3] For example, in American English, the un expression is treated as a singular for the purposes of the agreement, although it is formally plural. His family supported him in his time of mourning. In this example, it is not a prefix that is copied, but the initial syllable of the head “river”. Although there are no fixed rules for the use of prefixes, it would be useful to know what they represent. For example, “re” means “still”, “one” means “not”, “in” and “in” also means “not” and “say” means “the opposite of”. . . .