Kāna and Its Sisters

كان and its sisters come before a nominal sentence. The subject stays nominative, but the predicate becomes accusative:

• كان was, أصبح and صار became
• ما زال is still, ظل stayed, kept on
• ليس is not

Without vowel marks you see the accusative in three places: an indefinite masculine word gains an alif (جميل → جميلا), a masculine plural changes -ون to -ين (مشغولون → مشغولين), and a dual changes -ان to -ين or -تين (سعيدتان → سعيدتين). A verb that comes first stays singular but agrees in gender: كان المعلمون مشغولين (the teachers were busy), كانت البنتان سعيدتين (the two girls were happy). ليس takes person endings: لست، لستم.