English has been one of the most used languages of the world and it has a significant importance in the field of education. It plays a vital role to have the better view of the world and to have better access of the latest sources of knowledge and information. It is also a language of technology and both complement each other. In this modern era of Information and Communication Technology (ICT) English can be taught effectively with the help of computers and in that Computer Assisted Instruction or Computer Aided Instruction (CAI) is very useful as it lessens the burden of the teacher and makes teaching and learning interesting. Many studies have proved that students learn things at their own pace and convenience through CAI. It has also satisfied the need of the students of different age groups and proved effective in teaching different subjects so the present study was under taken to find out the effect of CAI to find out the effectiveness to teach English.