In Extensive Reading (ER) learners are exposed to large quantities of reading material simplified to be within their linguistic competence.This study investigates the overall effectiveness of ER and whether extra simplification increases effectiveness. It is proposed that the greater the degree of simplification, the more positive students' attitudes to leisure reading will be and the greater their gains in language proficiency. Twelve English langauge learners were randomly allocated to three groups. Over a 5-week period, Group A read graded readers at the intermediate level; Group B read intermediate material additionally simplified to an easier level and control Group C did not undertake ER. The reading was conducted during the participants' own time and involved one-to-one shared-reading sessions with the researcher for each participant of Groups A & B. The individual sessions were conducted by telephone for approximately 1 hour per week. The ER participants did 30 minutes daily of private e-book reading and kept reading diaries. An English language proficiency test and an attitude scale were administered pre- and post-treatment. Overall, the ER participants in Groups A and B demonstrated significant proficiency and attitudinal gains in cmparison to the control group. However, due to the small sample size of the extra-simplification group (B), no significant difference was established between the 2 ER groups (A and B). However, case studies involving one participant from each of the ER groups showed the extra-simplified material resulted in considerably higher proficiency and motivation towards reading. Further research is needed into the teaching of adult classes involved in the shared reading of materials that are modified for easy comprehension and that employ appropriate interactive strategies derived from one-to-one instruction.