The present book investigates the issue of mispunctuation in English and its impact on human vs. machine translation into Arabic. It analyzes how human translators and machine translation systems react when facing mispunctuated sentences, and the consequent implications of mispunctuation on the translation process. For translators to accurately convey the message from the source language (SL) into the target language (TL), paying attention to correct punctuation becomes crucial. The study is conducted by presenting 30 English sentences and evaluating their 1290 Arabic translations done by 54 BA, 14 MA, and 12 PhD students of translation at the Department of Translation, College of Arts, University of Mosul, besides 3 online machine translation systems: Google Translate, Bing Translator, and SYSTRAN. Statistical results show that mispunctuation affects, in varying degrees, the quality of translation due to the resulting inaccuracies, whether the translations are done by human or machine translation systems.