i used this book
https://a.co/d/0cQVpZSG I taught my kids at 4 with this book
We have taught our 4.5 year old (turning 5 this summer, going into kindergarten this fall) to read using this excellent phonics-based book: https://www.amazon.com/Teach-Your-Child-Read-Lessons/dp/0671631985 I like it because it has a natural progression from simple stories and simple sounds to more complex stories, so your kids don't get as bored. Also, critically, it TEACHES THE PARENT how to teach reading. I don't have formal training in education/phonics/literacy, so this part (coaching the parent on what to say to the kid to encourage them to sound out words) was key. There is a 40-ish page introduction that you, the parent, need to read first, BEFORE introducing it to your kid, which is all about how to use the book. But it's been great. We started when my child was 4, knew all her letter sounds, and seemed interested in reading and writing--for example, writing her name, and memorizing how to spell words like CAT and DOG. She is really enthusiastic about the lessons and is up to lesson 70. We do let her watch a TV episode after each lesson ;) I will agree with all the other commenters of course, that if your child isn't interested in it, don't push it! Continue reading fun stories to him or her (not just basic stories to teach reading). Make sure you are mixing it up and keeping them interested in books. Depending on their interest, they are starting to be old enough for you to read longer, wordier stories (like classic fairy tales) or even short chapter books like Roald Dahl, Narnia, or Frog and Toad. You can also check out graphic novels or books with no words at all! They will learn to read in kindergarten, and learning all the letter "sounds" is a great foundation. Also, they will probably develop interest once they start getting the hang of it. My child got really excited and motivated to read once she started being able to read words on signs.
