Owing to basic language differences, ESL authors often make some mistakes when writing their manuscripts in English. In this series, experienced trainer John McDonald shares six common errors ESL authors make and explains how they can be avoided. While the first three errors are related to the use of numbers and symbols, while the remaining address issues like tense usage, subject-verb agreement, and excessive use of simple sentences to convey repetitive information. John's explanations in this series makes it clear that thorough proofreading can help avoid these mistakes and, thus, is an integral part of manuscript preparation.