who should the child live with?

[Ellona]

Is it normal to have a 5year old choose who they want to live with after a split?

No it's not.
Who says it is?
The starting point is 50:50.

No. They should stay in their current home if possible, with the parent who they are used to spending the majority of their time with.

5 is far too young to think a massive decision like that through rationally and avoid being (intentionally or unintentionally) bullied or bribed by the less scrupulous parent.

A lot of 5 year olds would pick the parent who lets them eat junk food and stay up as late as they like watching age inappropriate TV / playing x box over the one offering home cooked fresh food and enforcing a sensible bedtime, reading them stories and making sure they do their reading practice ...

50:50 is the assumption unless there is a reason for a different split.

Not if it's as straightforward as that suggests, but I can think of circumstances where their opinion should be taken into consideration.

Yep, I agree they should absolutely be listened to. If they are very much opposed to living with one parent that should be looked into, especially if there's a chance of abuse or neglect.

They shouldn't, and wouldn't, just be asked "Mummy or Daddy?" and expected to pick one though!

Starting point is 50/50 unless either parent doesn't or can't.

No, they don't get a final say. They should get a chance to be heard, though. There's a world of difference between what a 5 year old wants and what's actually best for them long-term. The adults around them have to balance the childs wants and needs with their own assessment of each situation.

Thank you for your advice ladies.
Basically my friends partner has said he thinks the child should be able to choose if they split (things haven't been going great for them) but I think it's unfair as the child would always say Dad because he has more time to be the fun one

Well then he's a dick and that's not what the law prescribes. Kids don't have a legal voice until about 10/11 in terms of preference. (In the uk)

The arrangements should reflected what is best for the child.

That is absolutely not the same as letting the child choose.

Most children would choose chips or chocolate for tea every day. But it isn’t in their best interests to let them have that every day.