Second, when the rules of combining sounds into words (i.e., phonotactic constraints/rules) are different in the learners’ mother tongue from those of the target language, they cause problems for learners because these rules are language specific as they vary from one language to another.
Thirdly, since the rhythm and melody of a language determine its patterns of stress and intonation, learners may transfer these patterns into the target language. In summary, while there are other factors that influence the learner’s L2 pronunciation acquisition (Graham, 1994), the factors reviewed above may help ESL/EFL teachers consider what learners from different backgrounds are likely to face when learning English as a second language. These factors would enable the teachers to identify the difficulties in the pronunciation of the target language experienced by non-native speakers in order to help them overcome their foreign accent and consequently improve their pronunciation. In addition, they would also enable teachers to provide efficient pronunciation instruction and
design their teaching methodology according to students’ needs.