This paper deals with morphological adaptation of Anglicisms used by speakers of Serbian when posting comments on YouTube. Given the main focus of our re- search, we rely on Prćićʼs classification of Anglicisms in Serbian. According to Prćić, there are three types of Anglicisms in Serbian: raw, obvious and hidden. Raw Anglicisms are not adapted in any way and are used as such in Serbian. For example, in all-inclusive aranžman, all-inclusive is an example of a raw, non-adapted Anglicism. Obvious Anglicisms are Eng- lish words that have been fully adapted to the linguistic system of the Serbian language. These anglicisms are orthographically, phonologically, and morphosyntactically Serbian, but it is obvious that they are loanwords. For example, lajk (eng. like), daunloudovati (eng. download)... Hidden Anglicisms refer to the phenomenon of Serbian words and phrases being used in the same way as their English counterparts. For example, Serbian word kopija might develop the same meaning as its English counterpart copy. In addition to Prćićʼs classification, we simultaneously rely on Filipovićʼs ideas about the primary and secondary morphological adaptation of English loanwords. Primary morphological adaptation entails deciding how the word will be written and pronounced in Serbian. After that, the word undergoes secondary morphological adaptation, that is, it must be used in accordance with all the morphosyntactic rules of Serbian. New forms of the word (for example, adjectival forms...) are derived using standard Serbian affixes. The goal of this paper was to describe the ways in which subscribers adapt English words, if they happen to do that at all. The analysis of the morphological adaptation of An- glicisms in Serbian is based on a corpus of 100 Anglicisms that Serbian subscribers incorpo- rated into their comments. The research results were the following: (1) the most commonly used Anglicisms are raw and obvious Anglicisms; (2) both raw and obvious Anglicisms undergo secondary morphological adaptation (for example, klilbejterski, contentom); (3) ex- amples of hidden Anglicisms were not found in the corpus; (4) subscribers sometimes adapt only one or one part of the Anglicism (for example, family frendli, clickbejter; Ajde lajk ko zeli part 2); (5) morphological adaptation is varied, arbitrary, and entirely subjective. Given that the use of raw and obvious Anglicisms, particularly on different social media platforms, such as YouTube, remains unabated, it is necessary to raise awareness about the importance of proper morphological adaptation of foreign words in Serbian, which is one of the essential prerequisites for their proper usage and preservation of the Serbian language.