What is a good way of retaining a student's interest in the subject especially something as vast as English literature?

spice it up with lilttle bit of fun,that will definitely do !!!

To have students' interest choose simple texts with adventurous style, avoiding coplicated themes and difficult vocabulary.

Hamza has got it spot on. I would supplement his answer by suggesting that a teacher introduces some of the more "adventurous" classics, Ivanhoe, Treasure Island etc as well as most things by Dickens, Oliver Twist is very "readable" for many reasons. I would avoid Shakespeare unless it is absolutely necessary as part of their curriculum, I say that as someone who struggles with anything Shakesperian!! Shame on me!!

Good instruction is good instruction, regardless of students' racial, ethnic, or socioeconomic backgrounds. To a large extent, good teaching—teaching that is engaging, relevant, multicultural, and appealing to a variety of modalities and learning styles—works well with all children.

These "ideas at work" range in complexity and magnitude. They represent concepts that cut across content areas. They overlap so comfortably that they sometimes look like separate facets of a single gem. They are as much about attitude and general approach as about specific pedagogical techniques and classroom application. They have a few characteristics in common:

• They tend to be inclusive, not exclusive.
• They work best in context with other ideas and concepts, not in isolation.
• They often focus on students working within social situations rather than alone.
• Their activities, techniques, and goals are interactive and interdisciplinary, realistic rather than esoteric.
• Possibly most important, they empower students to be actively involved in the processes of their own learning, rather than passively receptive.

Depends on age/level…Try to keep them interested by providing concrete examples from modern life and of famous people/personalities; and introduce some fun and competition with some role plays and reward- if applicable. Another technique that could also work is building trust with the most difficult elements of the group by getting them involved, but make sure you don’t forget the other elements. To put it in a nutshell, find what they like and be interested in what they are interested in (sports, fashion, music, movies…, etc. and even cartoons).