Sometimes Dyslexic students struggle with words that others would consider simple. 20% of students struggle to read due to a different way that their brain patterns letters and words. Anything about language can be a challenge for a Dyslexic child but it does not mean that they are behind developmentally.
Reading is difficult for people who have Dyslexia.
There are several approaches to teaching Dyslexic children.
There are also resources that show you what having Dyslexia is like.