tends to be omitted whenever the contraction "it's" can be used in English. Thus, il may be omitted from the second sentence above: "Es ver que ille arriva deman". In addition, subject pronouns are sometimes omitted when they can be inferred from a previous sentence: Illa audiva un crito. Curreva al porta. Aperiva lo. She heard a cry. Ran to the door. Opened it. Esperanto Similarly, Esperanto sometimes exhibits pronoun deletion in casual use. This deletion is normally limited to subject pronouns, especially where the pronoun has been used just previously: In "official" use, however, Esperanto admits of null-subject sentences in two cases only: (optional) in the 2nd person imperative (N.B. The Esperanto imperative is often named "volitive" instead, since it can be conjugated with a subject in any person, and also used in subordinate clauses) Venu! Come! Vi venu! You [there], come [with me]! (pronoun added for emphasis) For "impersonal verbs" which have no semantic subject. In English or French, an "empty" subject is nevertheless required: Pluvas. It is raining. FR: Il pleut. Estas nun somero. It is summer now. FR: C'est l'été à présent. Estas vere, ke li alvenos morgaŭ. It is true that he will arrive tomorrow. FR: C'est vrai qu'il arrivera demain. (In this latter case, the sentence is not really no-subject, since "ke li alvenos morgaŭ" ("that he will arrive tomorrow") is the subject.) Contrary to the Interlingua example above, and as in English, a repeated subject can normally be omitted only within a single sentence: Ŝi aŭdis krion. Ŝi kuris al la pordo. Ŝi malfermis ĝin. She heard a shout. She ran to the door. She opened it. Ŝi aŭdis krion, kuris al la pordo kaj malfermis ĝin. She heard a shout, ran to the door and opened it. See also Notes Bibliography Alexiadou, Artemis 2006. Uniform and non-uniform aspects of pro-drop languages. In Arguments and agreement, ed. P. Ackema, P. Brandt, M. Schoorlemmer & F. Weerman, 127-158. Oxford: Oxford University Press. Barbosa, Pilar MEL Duarte, and M Kato. (2005) Null Subjects in European and Brazilian Portuguese. Journal of Portuguese Linguistics. () Biberauer, Theresa, Anders Holmberg, Ian Roberts and Michele Sheehan (eds). 2010. Parametric Variation: Null subjects in Minimalist Theory. Cambridge: Cambridge University Press. Cook, Manuela. (1997) A Theory for the Interpretation of Forms of Address in the Portuguese Language. Hispania, Vol 80, Nº 3, AATSP, USA Chomsky, Noam 1981. Lectures on government and