The role of the mother tongue in second language learning has

recently sparked debates and controversies. This study investigates the

use of the first language (L1) in the learning and teaching of English as

a second language (L2) in primary school. The main goal of study is to

determine to what extent and in which instances the first language (L1)

is used and the response of second language educators when they hear

the first language (L1) in their classroom. Most educators feel that the

use of the first language (L1) should be minimized and they feel guilty

if they use it a lot. When challenged, they find it difficult to explain

why. Contrary to the use of the first language (L1), it is generally

assumed that English should be learned through English, just as you

learn your mother tongue using your mother tongue. On the other

hand, the idea that the learner should learn English like a native

speaker or try to 'think in English' is viewed as an inappropriate and

unachievable concept.

This Paper investigates the problem that EFL learners of First Year in English Department at Alassaba College commonly come across issues when pronouncing the th sounds /θ/ and / ð /.It is reported that they frequently substitutes /th/ for the voiceless sound /θ/ and /θ/ for the voiced sound / ð /. Researchers believe that learning the differences between these sounds can help the students of Arabic to be able to pronounce English consonants properly. This is due to the fact that first language can affect learning the second language. Whenever the differences are identified it will be easy for students to learn. The purpose of this study is to explore the interference of mother tongue in pronunciation field that was made by learners of English Department dealing with English sounds/θ/ and / ð. The participants were 30 EFL learners with Arabic background as their mother tongue. To help students overcome their difficulties, comprehensively instructingthe way to pronounce /θ/ and / ð / sounds correctly, using minimal pairs with numerous examples, and creating an inspired learning environment for the students to practice pronunciation are recommended, and recording the students’ pronunciation and analyzed using contrastive analysis.