What to write in a book for a grandchild, when it is the one that gets kept

Every page of advice on this subject will offer you a version of "may your life be full of love and laughter". A stranger could have written that. A greetings card did write that. It is not what a grandchild needs from you.

What you have, and nobody else in that child's life has, is the other end of the story: you knew their mother or their father as a child. You know what they were like at exactly the age this child is now - which book they demanded four nights running, what they were frightened of, how badly they behaved at three. Put that in. It is the only thing in the book the child could not get anywhere else, and it is the passage they will read out loud to their own children.

The second thing you have is evidence of yourself. A grandchild who is eight when you write this may be forty when they read it properly, and by then your handwriting, your turn of phrase and the fact that you thought they were worth the effort are the whole message. You do not need to say anything wise. You need to be recognisably you on the page.

If you have not chosen the book yet, the guide written for grandparents covers what actually gets read at each age rather than what looks impressive when unwrapped. Take a look

Take one as it stands and change the name. The ones that work are the ones that sound like speech rather than like a card.

"For {name}, from Granny. I have wanted to write in a book for you since before you existed."

"To {name} - you are the best thing that has happened to this family in thirty years, and I am counting."

"For {name}, from Nana. Read this one to me when you can, and I will do the voices until then."

"To {name}: I have loved you since the phone call, long before I met you."

"For {name} - from Grandma, who is very glad indeed to be Grandma."

"To {name}, from your grandmother. Ask me anything, for as long as I am here to be asked."

Grandfathers tend to write less and mind more about getting it wrong. Short is not a failure here; unsigned is.

"For {name}, from Grandad. I am not a man for writing things down, so read it twice."

"To {name} - from your grandfather, who is already planning what the two of us are going to build."

"For {name}: your grandad chose this book himself and would like that noted."

"To {name}, from Pop. You have the best of your mother in you already."

"For {name} - from Grandpa, who intends to teach you everything your parents would rather he did not."

These are the ones worth the trouble. A child cannot learn this from anybody but you, and the older they get the more it is worth.

"For {name}. Your mother was exactly your age when she made me read this one four times in a row."

"To {name} - your dad hated bedtime too. He turned out well enough. Mostly."

"For {name}: your mother was a terror at three and is a marvel at thirty-four. Take heart."

"To {name}, from Grandma. Your dad was small once. I have the photographs and I intend to share them."

"For {name} - this was your mother's favourite. She will not remember it. I do."

If you are writing in a book for a christening, a new baby, a birthday or a first day of school, the lines for those occasions are gathered here. Take a look

A great many of these books are bought precisely because the grandparent cannot be in the room. The inscription is doing the work of presence, so let it say so plainly rather than pretending the distance is not there.

"For {name}, from Granny, who is a long way away and thinking about you anyway."

"To {name} - six time zones, one book, all of my love."

"For {name}: I cannot read this to you tonight, so I am writing in it instead."

"To {name}, from Grandad, who is nearer than he looks on the map."

Four generations in one room is rarer than it sounds and almost nobody writes it down. If that is you, say the number - it is the detail the child will repeat for the rest of their life.

"For {name}, from your great-grandmother. There are four generations of us now, and you are the best dressed."

"To {name} - I am ninety-one and you are one. We have more in common than you would think."

"For {name}: your great-grandfather was a reader too. You come by it honestly."

"To {name}, from Great-Granny. I have met a great many babies. You are the current favourite."

Once they are past being read to, the inscription changes job: it stops being for the parent reading aloud and becomes a note from one reader to another. Write up to them.

"For {name} at ten, from Granny, who has run out of toys you want and is falling back on books."

"To {name} - you are too old for me to read this to you, which is the only part of you growing up that I mind."

"For {name}: I chose this because it is good, not because it is easy. You are ready for it."

"To {name}, from Grandad. Come and argue with me about the ending."

Grandparent names are chaos - Granny, Grandma, Nana, Gran, Gigi, Mimi, Pop, Grandad, and whatever the child invents at eighteen months and everybody then adopts for life. Sign with the one the child actually uses, because that is the name the sentence has to sound like.

Then put your real name in brackets after it, once: "Granny (Eileen)". In forty years, when this book is being read by somebody sorting out a house, "Granny" is one of four and "Eileen" is a person. It costs you six characters and it is the difference between a keepsake and a puzzle.

And date it. A dedication with a date on it stops being a sentiment and becomes a record - which, given who is reading it and when, is the more useful of the two.

Some of these are written with one eye on a time when the writer will not be there, and there is no reason to be coy about it. It is the most natural thing in the world to want to leave something in your own hand, and a book is a better place for it than a drawer, because the book gets opened.

Two things make that kind of inscription land. Do not give advice - advice ages and the child will have had plenty. Give specifics: what you did for a living, what you were like at their age, what you thought when you first saw them. Second, write it as if they are in the room, in the present tense, not as a message from a distance. "I think you are going to be very good company" reads better at forty than any farewell.

And keep it to a page. The instinct is to say everything. What survives is one page that sounds like you.