Mr. Geo has worked continuously as an English teacher in schools in Britain for 16 years. Over this period, exposure to different learner groups has provided familiarity with the specific English problems of speakers of a wide range of other first languages, including Mandarin, Arabic, French, Malay, German, Spanish, Greek, Hindi, Malayalam, Polish, and Bantu and Nilotic African languages. Furthermore, giving individual tutorials in the international environment of Cambridge has added insights into other major languages of the world, particularly those from the Indian subcontinent, Turkey, Iran, Japan, West Africa, and the Portuguese-speaking countries, which resulted world's first Facebook live English classes. (www.facebook.com/giosenglishandwww.youtube.com/giosenglish ) Constant exposure to the English grammatical weaknesses of such a wide range of learners, many informally noted down, analyzed using insights from modern Applied Linguistics, and subsequently verified through further exposure, has provided a strong intuitive appreciation of common grammatical errors in academic writing and their likely reasons – information not easily found in standard grammar books.Such learners are numerous in the educational and professional worlds, and respond positively to courses and materials that seek to meet their specific needs. Learners of this kind do greatly need a standard revision of mainstream grammatical topics like articles and tenses which is covered by Gio's English App.