This cross-sectional study attempted to determine whether the English negation errors made by the University of Jordan's students were similar to the English negation errors proposed by Klima and Bellugi (1966), or influenced by the Arabic syntactic structures of negative sentences. Data of negative structures were gathered, and error counts were calculated. Results showed some correspondence to Klima and Bellugi's proposed system but only in stages II and III. The effect of Arabic was significant on do- transformations. Students did not formulate a rule-governed system of negatives because their responses were not consistent along with English tenses. Students' developmental sequence of negatives and their imperfect mastery over tense may have accounted for most errors. However, the mismatch between errors and correct responses decreased as students moved through higher levels of English study. (Contains 5 figures and 6 tables.)