Background: The Eastern Cape province in South Africa is a multilingual province where isiXhosa is the most widely spoken indigenous language. Learners seldom use English at home, and it remains, largely, the language of learning and teaching used at school. With the advent of dynamic technology, learners are widely exposed to social media, and those who use the language of social media networks tend to include it in their academic activities at school. Objectives: The purpose of this article is to report on the orthographic errors in English Second Language Grade 10 essay writing caused by the use of social media, particularly WhatsApp. Method: The study was carried out at three randomly selected high schools in one district in the Eastern Cape province, South Africa. The study used a quantitative approach to data analysis, but with a survey research design. Random sampling techniques were used to select 180 learners from three schools. The data collection instrument consisted of learners’ narrative essays. The data were analysed quantitatively and are presented using tables and graphs. The orthographic errors in the essays were identified and quantified. Results: The findings of this investigation shed light on the influence of social media on learners’ writing. Some of the findings included use of abbreviations, unnecessarily shortened words, and use of numbers instead of the complete word form. Conclusion: Recommendations are made on how teachers can help learners avoid this erroneous use of language in their writing. Suggestions are also made on how textbook writers and the Department of Basic Education can assist and support teachers in this process.