Every parent eventually hits the same moment: you open a treasured story collection, ready to share the magic, and within ninety seconds your four-year-old is upside down on the sofa while your nine-year-old sighs that it is a baby book. The stories have not changed. The mismatch has. Matching a tale to a child's attention span, sensitivity and reading confidence is the difference between a bedtime ritual they beg for and a nightly negotiation you both dread.

Start with the child, not the bookshelf

Before you choose anything, answer three questions about the child in front of you tonight, not the child in the school photo from last year.

• Attention span: a two-year-old can usually manage five minutes, a five-year-old closer to twenty, and an eight-year-old a whole short chapter if the plot is moving.
• Sensitivity: some children adore a delicious shiver; others will lie awake for a week worrying about a wolf. Think about what frightens your child specifically, not what frightened you.
• Reading confidence: listening level and reading level are different things. Most children understand stories roughly two years above the level they can decode themselves, so a fluent seven-year-old may still want you to read the longer tales aloud.

Ages two to four: rhythm, repetition and a safe ending

At this stage the plot matters far less than the sound of it. Very young children are learning the shape of stories, so cumulative tales where the same line returns again and again work beautifully. The Enormous Turnip, The Gingerbread Man, Goldilocks and the Three Bears and gentle versions of The Three Little Pigs all give a child the joy of joining in before they can read a word.

Keep sessions to five or eight minutes, and use an illustrated edition with a page of text at most per picture. The ending should be reassuring. The villain is best outwitted, outrun or taught a lesson rather than eaten, boiled or chopped. Save Hansel and Gretel, with its abandoned children and oven, for a few years yet, and be cautious with unedited Little Red Riding Hood. If a story ends with everyone safe, a small child can carry a surprising amount of excitement along the way.

Ages five to seven: the golden window for classic tales

This is the sweet spot. Children at this age can hold suspense, follow cause and effect, and understand that a character can be frightened without actually being in danger. It is the perfect moment for Jack and the Beanstalk, Cinderella, Rumpelstiltskin, The Frog Prince, The Ugly Duckling and The Elves and the Shoemaker.

Do not feel you must sanitise everything. A five-year-old who knows the wolf is coming will grip your arm and ask for more, provided the ending restores order. What helps is how you tell it: slow down before the frightening part, keep your voice steady rather than dramatic, and never rush past it. If your child asks to skip ahead, skip. That is not weakness; it is good reading.

Expect fifteen to twenty minutes, or one complete picture-book version. Some children in this bracket still want the toddler treatment, and that is entirely normal. Follow the child, not the birthday.

Ages eight to ten: longer arcs and uncomfortable questions

Now the tales can stretch. The Snow Queen, Beauty and the Beast, The Wild Swans and The Little Mermaid in its original form all offer chapters, journeys and real emotional stakes. This is also the age when children start noticing that the hero is not always heroic. Jack stole from a giant. Cinderella's stepsisters were mutilated in the Grimm version. The Little Mermaid dies.

Rather than hide this, use it. "Was that fair?" is a wonderful question at bedtime, and it teaches a child that stories are things to think about, not just absorb. If your child is reading independently, remember that the language of classic tales is often archaic and the sentences long. Reading aloud above their own reading level keeps the pleasure alive while their skills catch up.

Ages eleven and up: retellings, twists and the stories behind the stories

Older children rarely want to be read a "fairy tale", but they will happily read a retelling, a fractured version or a story told from the villain's point of view. Introduce the idea that these tales were collected and rewritten by different people over centuries, and that every version carries the worries of its own time. Many eleven-year-olds find this genuinely fascinating, and it opens the door to writing their own versions. Keep reading aloud if they will let you; the shared ritual matters more than the reading practice.

Practical ways to test a story before you commit

• Read it yourself first. Ten minutes now saves a difficult conversation at 7.45pm.
• Check the middle and the end, not just the opening. That is where the abandonment, the transformations and the losses usually live.
• Decide your scary-bit strategy in advance. Shorten it, soften it or name it calmly, but do not pretend it is not there.
• Let your child choose between two options rather than the whole shelf. It gives them control without overwhelming them.
• Offer an escape hatch. "Say the word and we stop" makes children braver, not more fearful.
• Try a chapter before buying. A borrowed library copy or a sample read aloud tells you more than any age guide on a cover.

A final reassurance: there is no correct order and no schedule to fall behind. A ten-year-old who still loves The Three Little Pigs is not missing out, and a six-year-old who asks for The Snow Queen can probably handle it. What children remember is not which tale you chose on any given night, but that you sat down, turned the page and made the old stories theirs.