Language learning is the process of learning to speak and understand a foreign language. It helps children to acquire practical commands of language. It is a result of deliberate and conscious effort for a better understanding of foundational skills of language learning.Diagnostic test:A test that is administered at the end of a concept is called a Diagnostic test. These tests are designed to point out inadequacies in specific skills.The main objective of a diagnostic test is to locate areas in which additional instruction is required and for which teaching methods need to be improved.Diagnostic tests are administered at the end of the language course to locate and identify the areas of learning difficulties of the students with a view to plan remedies.These tests are very helpful in the process of language learning as it helps the language teacher to know the difficulties in the learner's understanding and to diagnose those difficulties with the necessary help.Hence, we conclude that locating and identifying the areas of learning difficulties leads to diagnostic testing.Hint Achievement tests are universally used in the classroom mainly to measure the knowledge and skills students learned in school or to determine the academic progress they have made over a period. Proficiency Test measures how well an individual has mastered a language. It is the ability of a person that transfers meaning in production and comprehension to use language with a level of accuracy.