How do you teach your child to read WORDS without memorising especially when reading story book? My boy's teacher comments that my 4 year-old is merely reading by memorising the sentence. How do I make him learn to read words by actually recognising them?

Is your child currently learning phonics? That helps to build up a foundation in reading as they will learn how to put the different phonetic sounds together and form words. Alternatively you can also use flashcards to go through individual words with him. I paste word cards around my son's room to get him to remember how to read the words. Expose him to words rather than just stories.