The following examples come from the Serbokroatic: another characteristic is concordance in participations that have different forms for different sexes: in standard English, for example, it can be said that I am or that he is, but not “I am” or “he is”. This is because the grammar of language requires that the verb and its subject correspond personally. The pronouns I and him are the first or third person respectively, just as the verb forms are and are. The verb must be chosen in such a way as to have the same person as the subject, unlike the fictitious agreement based on meaning.   For example, in American English, the un expression is treated as a singular for the purposes of the agreement, although it is formally plural. The part of the past is often used in forms of time assembled with the auxiliary forms to be or have, such as the narrative form: I have eaten or I am out.