Writing as a productive skill is challenging for the learners as it requires rich linguistic and cognitive abilities to match words with ideas well. A learner of any language as Second Language (SL), for example English, Arabic, Chinese, or German, enters an early, natural, and inevitable stage of making various errors in writing compositions. The errors could be due to dissimilar linguistic systems of the two languages (L1 and L2) or the lack of understanding the SL linguistic rules. This study focuses on investigating the frequent and common inter-lingual errors (the negative influence) committed by Arabic-speaking learners of English as Second Language (ESL). The study is based on Error Analysis (EA) of the essays of a group of English major undergraduate students from the University of Bisha, Al-Namas, Saudi Arabia. Contrastive Analysis Hypothesis (CAH) is included to predict most of the errors in the collected samples. The findings of the study show that common errors in the data are interlingual (54.03%). The errors within the Grammatical Category include the misuse of tenses, dropping the subjects, dropping verb to be-copular and word order misplacement. The majority of errors in the study are due to the interference of L1 linguistic system including the different orthographic, phonological, morpho-syntactic components. For instance, the participants’ dropping subjects in English can be attributed to the fact that Arabic as L1 and as Null Subject Language (NSL), unlike English, allows subject drop. The results also find that within the Lexical Category, preposition and article errors are the most frequent errors and that spelling errors are the most dominant errors within the Mechanics Category. The study gives some pedagogical implications and suggestions to avoid and minimize the interlingual errors of such type. For instance, teachers need to focus more on enlightening their students about the contrastive language systems from the early stage of learning ESL.