Proofreading is a process of identifying typographical, linguistic, and positional errors or omissions. Proofreading, as part of a collaborative process, can reveal gaps and weaknesses in the writer’s grammar and syntax, and offer teachable moments and learning opportunities that provide valuable individualized feedback. In this section, we focus on grammatical errors in theses and dissertations. Grammar is a set of certain rules. The grammar of English consists of rules that control the formation of English sentences. Grammatical errors refer to errors in following the language rules about combining words into phrases, clauses, sentences, and so on. It can be determined as morphological and syntactical errors. Grammatical errors are divided into four categories based on the surface strategy taxonomy. These errors are omissions, additions, misformation, and misordering. Omission can also be called a deletion. An omission error is the missing of one or more items that must exist in a sentence or utterance. It happens if the lexical item which should be present is omitted or deleted. An addition error is an error that can be identified by the presence of an item that must not appear in a sentence or utterance. Misordering occurs when a writer puts an item in the incorrect place in a construction. While misformation is the wrong form of the structure. In conclusion, we know that determining good grammar in writing is the most confusing thing. The solution that we can do to improve grammar, especially in this digital era, is by utilizing technology, in the form of a website or websites. This technology plays an important role in the proofreading process, one of which is grammar problems, for example, grammarly.com. However, apart from modern technology that can easily help, a manual proofreading process is still required to ensure good-quality writing. Several other professional service websites offer proofreading services, such as satupro.com, rajatulis.com, papertrue.com, and proofreadingpal.com. On these websites, proofreading services are handled directly by reliable proofreaders/experts in their fields. Illustrated and written by: Nur Lena Budiarto, Pamela Anisa Anderson, Rizki Yulia Agustin, and Safira Yunizar