Not sure if you're ready for a baby? Then why not borrow one and find out. AMINATTA FORNA did just that
Within months of the birth of my nephew, Tejan, I (a non-mother) published a book on the rigours of modern motherhood. I argued that urban, Western societies are divided between the haves and the have-nots - those with children and those without. We have a generation of thirtysomethings who have no experience of children until they have their own, and then they find themselves reeling from the unremitting responsibility. I suggested we all help each other, take a baby on loan and give the parents a break. How could I hold my head up if I didn't put my money where my mouth was? I volunteered to take full charge of my nephew for a day every week.

Minus two months

Terrible anxiety dream. I am looking after the New One and my Sister is due any moment. Suddenly realise that I have entirely forgotten to feed or change him. When I take off the weighted nappy, the baby, which previously looked large and healthy, is suddenly small and shrivelled.

Three months

Left in sole charge at 11am. Baby oblivious. Sit still and wait for something to happen. House seems very quiet, very empty. Good. Succeed where all parents have failed - look after baby and read newspaper. I put the Moses basket on the bed and sit on the edge bouncing up and down at a moderate pace. Almost get to features section but settle into an article, forget to bounce and the Shrimp wakes and shrieks. Relocate to the park, where he promptly falls asleep again. Sister returns after two hours. Seems impressed by newspaper trick.

Still three months

Encourage sister and husband to go to lunch sans bebe. Extremely large bag of baby goods deposited on the floor. Change nappy. Accidentally ripped the side tags off the first two, but put on the third (and last) successfully. Even the basic disposable nappy has fallen victim to over- design. Investigate contents of bag. Find some clothes, which I dress him in. Sweater proves a challenge. Remember only similar experience is of dressing dolls, which I solved by breaking their arms or pulling them out of their sockets. Not applicable.

Sister and husband return suddenly. She asks why baby is wearing dirty clothes. Also points out that nappy is on backwards. I remind her of our deal - that she wouldn't go all Perfect Mother on me. She laughs. Too long and rather loudly.

Four months

Excellent start deteriorates to meltdown. Baby arrives and sleeps while I gossip with my sister. Eventually she leaves to work on her thesis. Only six hours to go.

The Shrimp looks so peaceful, sucking air and blowing bubbles. Try to relocate to where I left the paper without waking him. Baby wails if I sit down, but my back hurts if I stand up. My mother showed me a sort of on-the-spot shuffle, which I emulate. It sort of works, only I can't keep it up. Wonder where S has disappeared to.

At 4pm my husband, S, returns and manages crisis while I lose it, the result of hours of low-level tension and mind-numbing boredom. The Shrimp eventually falls silent. Later, ask sister a) how do you know what he wants b) what, in fact, does he want. She replies a) try everything b) to be held continuously, 24-hours-a-day.

Consider alternative ways of rescinding agreement.

Five-and-a-half months

Now have my own push chair, high chair and cot. They take up a lot of space. The pushchair is of obsolete design, heavy and inoperable. It has replaced the papoose front-loading sling, into which I never succeeded in manoeuvring the Tiny One. Strangers used to watch me struggle and think what a useless mother I was. Spend all day in the park. Have to leave the pushchair outside when I get back, because I can't work out what to do with him while I carry it upstairs. Hope someone will steal it. Miss lunch for same reason, which makes me grouchy. Ask sister when she eats. She doesn't.

The dog, which previously loathed human infants, has begun to threaten anyone who crosses a demarcation area approximately one yard around Tiny One.

Six months

Baby-proof the house. Amazing that some people use professionals for this. Buy pack of "corner bumpers" from Ikea and stick to the corners of my steel kitchen units.

Nine months

Flee kitchen - I somehow failed to notice that all my pots and pans were suspended from meat hooks round the preparation table. Infant careens around sitting room in state of perpetual motion. Rescue African sculpture. Still recovering from sight of l'enfant terrible swaying unsteadily with ostrich egg held above his head.

Spend day in park ... again.

One year

Tiny One has come to stay for five weeks while his new home is renovated! Mercifully, parents have come too. Sister worried I'll never have a baby if we have to share a house. Fine, say I.

He definitely, definitely said "atta", (part of) my name today!

One year plus

I now know which cries matter ("duh, duh, duh, duh") and which don't ("waah"). At supper three out of four of us agree the sound we hear is a serious one, except S who has taken a disciplinarian stance over bedtimes. I rush to fetch baby. We were right. Tiny One won't be comforted and throws himself sobbing around the room. My heart aches. Afterwards, he won't look at his parents. His shoulders, less than a handspan across, face squarely away from them. He communicates only with me. I feel a little smug.

14 months

S has decided to crack the sleep thing and reads The Baby Book of Sleep. He is successful at the first attempt. Apparently we should soothe him but not pick him up. It has to be fluke, but this is a new side to S.

15-and-a-half months

S is Tejan's new hero. Sister says it's the same with her husband, Mervyn. Apparently, it's a boy thing.

Clear up after party, hindered by toddler intent on helping. Set him to work collecting butts and bottles from the grass. Works well.

15-and-three-quarter months

Take him to Bunty's, a friend who recently had first baby - a boy. Beautiful couple, beautiful house. Babes performs the careening trick again, into Tom Dixon furniture.

Perfect day, otherwise. No upheavals. Pretend he is ours. Look at S with new eye. On the way back, anxiety dream turns into reality. Running through checklist we realise we have forgotten to change him. Divert to house for a quick fix before returning him to his parents. Fall asleep on their sitting room floor and miss party.

16 months

Babes' first word is "Mab", our dog's name. Everyone agrees. S and Babes are bonded like glue. S is possessed of much patience and apparently genuine love of toddler games. I have now sunk miserably in the popularity stakes.

Nursery reports that Tejan picks up cigarette ends in the park.

17 months, one week

My first hardcore nappy. Something I have contrived to avoid, either by persuading my sister to do it before she leaves or blackmailing my husband. It makes me gag. Strip the foul-smelling Cherub and stand him in the bath, where I hose him down. He laughs at me.

18 months

Back from holidays. Babes arrives to collect his Cuban maracas and shouts "Spider" from the window. Afterwards all settle down to watch a video, made by Mervyn, starring Babes playing with a hose. I used to find those videos so tedious.

Bunty calls and offers me Tom Dixon table on a long loan.

Aminatta Forna is author of `Mother of All Myths', HarperCollins, pounds 7.99.