Learning to read does not happen as naturally or at as young an age as learning to speak.
Children need to intentionally work on literacy to master this skill. In addition, English is filled with inconsistencies, and these make the language more difficult for children with dyslexia to decode or encode.
If you are like the majority of native English speakers, you might not even be aware of these inconsistencies while you speak. But when it comes to reading and writing, these inconsistencies make English a tough language for learners and users.