This thesis has dealt with the area of tense in both Arabic and English. First, a contrastive analysis between the two languages was made. The areas of similarities and differences were discussed. Second, an error analysis was made to examine the validity of the predictions of the contrastive analysis. The errors committed by thirty Arab Palestinian students were analysed and discussed.To examine the validity of the results and to measure the frequency count and the correlations among the categories of errors, a statistical analysis was made.