I am hoping that someone here can help me to understand my son's WISC scores.

Recently we had the school counsellor do WISC-IV for my 7 year old and I am struggling to understand what the scores mean and how we can help him.

They gave me the scores in percentile rank:

Verbal Comprehension: 47 (average)
Perceptual Reasoning: 94 (superior)
Working Memory: 75 (high)
Processing Speed: 94 (superior)

Why is there such a disparity between his verbal comprehension and other scores? What does this mean?

His low verbal skills are reflected in his reading. He is reading slightly above his age level but but it is based solely on sight words - he cannot sound out words and is at 7th percentile for phonological awareness.

His hearing tested fine and the speech pathologists said that there were no underlying issues (eg APD).