Content clauses are subordinate clauses substituting for nouns. The paper focuses on the types of content clauses which existed in four Northwest Semitic languages of the second and first millennia bc: the Akkadian language of the Amarna tablets, Ugaritic, Biblical Hebrew and Biblical and Egyptian Aramaic. It seeks to find out whether all the four types of content clauses existing, for example, in English and Modern Hebrew, viz. subject content clauses, predicate content clauses, attributive content clauses and object content clauses, also existed in these four Northwest Semitic languages of the second and first millennia bc, and if not, which types existed in them, and to what extent.