How do you teach kids to read in their heads?

[TheFSMisreal]

I don't really know how to go about it. And I don't know how I would tell if they're reading or just looking. Where do I even start?

I told DD to whisper, then just move her lips without sound, then stop moving the lips. She did this over the course of a day while on holiday.

It just happens.

It does just happen for most. There are some children who need to be told though.

You aren’t going to know wether they are just looking or reading though, which can be a problem and can lead to bad habits.

Do you think DC is ready to read in their head or d is it more that you think they ‘should’ be?

I think it tends to happen fairly organically. You can check comprehension through discussion at the end of a chapter or story, plus getting them to read and occasional page to you gives you a clue as to how they're doing and an insight into their fluency etc

Oh that's clever, I'll definitely try the whisper thing. I have no idea with comprehension as it is to be honest. Just what he wants to say about it... Which is often just 'eh'

At about seven, I realised one day I could do it! Twas a revelation to me but it just happened.

with DS, issue was reading but not deep reading. When you read, you think you have remembered everything but you realize only when you write it down. Deep reading can be taught by asking DC to read same chapter 2-3 times and then read again but this time, after reading each para, revise in mind without seeing what you have read and cross checking.

It's important to continue listening to your child read aloud long after you think it's necessary. As they encounter more and more unfamiliar words in texts silent reading encourages skipping and ignoring. Reading aloud allows the word to enter the child's receptive vocabulary (and of course learn the meaning of new words)

From what time did you start to teach them? Reading always begins from learning alphabet and it's usually better to start from reading aloud for giving your child more practise, in this case a silent one will be easier later. However in the start it's better to combine both types and yeah, that whispering idea is really a cool one, we used it in the very beginning too, besides this method is nice for developing general child's concentration on smth which is really good too.
In our case for teaching reading we used our adult examples for creating an interest in our daughter and encouraging her, also various creative games for learning alphabet. It was the main step for us and I can say that idea with games was really better than simple practising with an alphabet book In this case also many apps, like zebrainy.com/, were useful too, children usually adore them because they're fun and interesting at the same time and because of that general process of teaching doesn't become boring at all. Besides in case of such games children usually have a choice in case of their game decisions so they can learn in that rhytm and order which are the most comfortable for them. And from my own experience I can say that it's really important, you'll really need to be patient in case of reading, especially considering that different children aren't equal in their speed for learning smth new.
I can recommend you to try a method of asking questions too about they read, it's a rather effective one. But again don't push too much, such questions should be like a friendly, interesting chat, not a long and always demanding process.