... Vietnamese students of English in using English modal verbs can, could, may, have to and must . An analysis specializing in errors in using English modal verb will bring about a number of benefits. ... fact that description and analysis of students& apos; errors play an important role in the improvement of the teaching and learning. Error analysis has been an interesting area, which has attracted ... benefits in language teaching and learning.1.5.4.1 Interlingual errors and mother tongue interferenceThe phenomenon of native language influences on the learning of a second language is called “intralingual”...