Abstract
This study aims at identifying the main impact of vocabulary size as a
predictor of reading Comprehension in educational stages.Accordingly, the lexical
knowledge of learners can be improved, and, in turn, enhanced lexical knowledge
might lead to higher levels of reading comprehension.The study also reveals that Saudi EFL
learners typically demonstrate an average vocabulary size of around 2,000-3,000
word families, which is far below the 8,000-10,000 word families needed for full
comprehension of university-level or advanced texts.In addition, teachers and students should be
aware of some major aspects of learning vocabulary such as the definitions of words,
synonyms, antonyms ,word collocations, and semantic and pragmatic
characteristics.The use of various methods of teaching are highly recommended for
assisting EFL learners in enlarging their lexical knowledge.The researcher used a
qualitative research method.