English language as a means of communication has globally gained ground in almost every sphere of life and society and, as such, has converted to an important language worldwide. The aim of this research work is basically to analyse mother tongue influence (MTI) on the learning of a second language through bibliographical and observational means, and the role it plays on students in El Carmen, whose mother tongue (L1) is Spanish in the process of the learning of English (L2) as a foreign language. A qualitative investigation method permitted the analysis of the oral production of the sample size and relevant bibliography that are related to the topic. The results obtained clearly demonstrated that L1 has influence on the learning of L2. A list of English words were taken into account to show how the Spanish language affects their pronunciation, and also phrases with regards to the use and application of grammatical rules in both languages. In conclusion, with exposure to audio-visual and written materials in the L2, practice of speaking and correcting mistakes, they gradually learn to replace the L1 sounds and grammar issues with the original sounds and grammar rules of the L2 that they have chosen to learn, in this case, English as a foreign language.English language as a means of communication has globally gained ground in almost every sphere of life and society and, as such, has converted to an important language worldwide. The aim of this research work is basically to analyse mother tongue influence (MTI) on the learning of a second language through bibliographical and observational means, and the role it plays on students in El Carmen, whose mother tongue (L1) is Spanish in the process of the learning of English (L2) as a foreign language. A qualitative investigation method permitted the analysis of the oral production of the sample size and relevant bibliography that are related to the topic. The results obtained clearly demonstrated that L1 has influence on the learning of L2. A list of English words were taken into account to show how the Spanish language affects their pronunciation, and also phrases with regards to the use and application of grammatical rules in both languages. In conclusion, with exposure to audio-visual and written materials in the L2, practice of speaking and correcting mistakes, they gradually learn to replace the L1 sounds and grammar issues with the original sounds and grammar rules of the L2 that they have chosen to learn, in this case, English as a foreign language.