People on Earth get in touch for diverse reasons such as trade, migrations, tourism, and work. These people speak different languages and desire to communicate. In this context, the language problem (language barrier) occurs in their communication because of differences in languages. This barrier does not prevent them from speaking because the communication desire obliges them to interact. But while interacting, words are borrowed from one language to another. Therefore, there is a co-penetration of linguistic expressions. That is, words of one language can be used in another one and vice versa. Such words, most of the time, undergo changes in spelling and pronunciation. Considering the case of Lontómbá speakers and English ones, one can notice that Lontómbá speakers have borrowed words from English through different contacts with English speakers (missionaries). Up to now there is not any scientific explanation about these borrowings that can help understand exactly the adaptation of the English borrowings in Lontómbá. Therefore, the problem that leads to conduct this research is the remarkable lack of a reliable scientific explanation of English loanwords in Lontómbá language. The aim of this article is to find out the phonological rules that govern the change in pronunciation of the English loanwords in Lontómbá language. After the analysis of a corpus of 100 English loanwords in Lontómbá, this paper has found out the phonological rules explaining the change in pronunciation of the English loanwords.