Potty

About 2.5 minutes at an unhurried pace, including a standard allowance for page turns, pictures and participation, from a word count of 100. Stopping for a longer conversation on every page will add more time.

Ages 2-3 in our testing, which is narrower than the publisher's range. With 1 sentence a page and vocabulary at 1 out of 5, it asks for that much attention span and no more.

Yes. It survives a fortnight of nightly repeats, which is the real test.

It helps that it has a refrain a child can join in with, and it asks the child questions to answer out loud. Those three features are what keep a wriggling toddler listening, far more than the subject matter does.

Probably, and fast. The book leans on a repeated refrain, and at 4 out of 5 for re-read tolerance it survives the nightly repeats that get a book memorised. Expect your child to chant the pattern back before they can actually read.

It is closer than most picture books. With 1 sentence a page and plain vocabulary (1 out of 5), a confident early reader can attempt it, though it is written to be read aloud first.

We tag it with toilet, independence and babies. Those are the threads that actually run through the book, not just the ones on the cover, which is how it earns its place on our themed lists rather than a keyword match.