I stopped teaching two years ago. Although I taught every year for 33 years, I am not sure I ever truly knew what I was doing.

Don’t get me wrong, through trial and error, I learned to teach in a way that helped children learn. My pupils made progress and often attained good results. But I wish I’d known then what I know now about the relationship between teaching and learning.

If I were able to begin my teaching career again, there are five things I understand today that would have helped me to teach more effectively back when I started out.

1. Curriculum is more than just content

I began teaching English in a sixth-form college, where the curriculum was treated as little more than the texts you chose to teach.

I now understand that the curriculum is so much more than this. It’s made up of what I call the “curriculum triumvirate”: content, adaptive teaching and assessment.

The relationship between these three elements is dynamic. You decide the content you want pupils to learn; you teach it to them in a way you hope will help them to learn it; and you use all the assessment information you can muster - from frowns on pupils’ faces to formal mock examination grades - to help you decide which aspects of the content they have actually learned.

If pupils haven’t learned what you intended for them to learn, you have to work out what it is about the way you taught that information that now needs adapting.

2. Children have to think hard to learn

As a young teacher, I was driven by Seneca’s maxim: “There is no learning without remembering.”

But it was Daniel Willingham’s mantra - “memory is the residue of thought” - that helped me to realise that pupils have to think hard if they’re going to learn anything.

If a pupil can make it through the school day without having to think hard, they will form no new memories; they will have nothing to remember and, consequently, they will have learned nothing.

Therefore, we have to teach in a way that maximises the time pupils are thinking hard.

3. Genuinely high expectations are crucial to pupils making progress

When I look back to the early days of my teaching, I know that I did not ask enough of all my pupils. It’s easy to say that you have the highest expectations - but what matters is the quality of learning opportunities you provide.

For our latest book, SEND Huh: Curriculum Conversations with SEND Leaders, Mary Myatt and I interviewed a Year 6 pupil who has autism spectrum disorder and attention deficit disorder. He mentioned how he liked work when it was difficult.

When Myatt asked him to tell us more, he said: “I like hard because it’s learning. If it’s easy, you’re not really learning, because you can just do it. But when it is hard you are thinking, so it stays in your head.”

Regardless of a pupil’s needs, they all need opportunities to complete work that allows them to think hard.

4. Be the expert in the room

I began teaching because I had discovered literature at university and thought discussing poetry would be a good way of earning a living. It wouldn’t even feel like work, I thought.

The problem was, I spent a lot of time in my first years of teaching letting pupils explore literary texts themselves. We wasted a lot of time.

In my liberal youthfulness, I eschewed the idea of telling pupils anything. Direct instruction, I believed, belonged to the grammar school classrooms of the 1950s. How wrong I was.

It’s clear to me now that knowing stuff - and explaining it in a way that makes it irresistible to pupils - is at the heart of effective teaching. Indeed, if you are not an enthused expert in the material you’re teaching, what chance do the pupils have?

5. Never assume pupils understand you

In my first year of teaching, on every single essay one pupil submitted, I wrote: “Don’t paraphrase”.

When I spoke to her about her progress, at the end of the year and more than halfway through the A-level course, she asked, with no hint of irony: “What does ‘paraphrase’ mean, Sir?”

I think all teachers now appreciate the importance of developing pupils’ vocabulary. But the curse of knowledge means it is still hard to remember to check yourself when you are in full flow in the classroom - and to acknowledge that corners of the classroom may not always have a flying clue what you are talking about.

John Tomsett is an education consultant and the former headteacher of Huntington School in York