# how to write something of something and something

I'm confused whether should I use plural when writing something of something and something.

For example: the dataset of A and B (A and B are the names of the dataset).

Should I use plural for 'dataset' here? My understanding is like this:

'the dataset of A and B' equals 'the dataset of A and the dataset of B'

So I should use singular for the 'dataset'

Mary and John each has their own respective car:

The cars of Mary and John

Mary and John share the same car

The car of Mary and John.

Mary and John is the name of a single car

The car Mary and John

The car has two names, either Mary or John

The car Mary or John

Choose one car from two cars

The cars Mary or John
A car Mary or John

Concerning the datasets ...

A and B each has their own respective dataset:

The datasets of A and B

A and B share the same dataset

The dataset of A and B.

A and B is the name of a single dataset

The dataset A_and_B

The dataset has two names, either A or B

The dataset A or B

Choose one dataset from two datasets

The datasets A or B
A dataset A or B

• Mary and John each has?? – Jim Oct 15 '14 at 5:32
• Iterate thro the list of mary, ..., and john, where each member has ... For this case, there are only two members in the list. – Blessed Geek Oct 15 '14 at 6:47
• Our employees each has a company issued tablet - for case where the list are all the employees in the company. – Blessed Geek Oct 15 '14 at 6:48
• I had not bothered to explain that this is point-form disjointed structure. – Blessed Geek Oct 15 '14 at 6:58
• This feels very wrong to me, but you argue it like it should be common knowledge so now you've got me wondering whether it's just something I never learned properly. But in my mind it's: "Mary and John each have," "They each have," "Each member has," "Our employees each have," "Each employee has," "Each one has," "Each of them has" – Jim Oct 15 '14 at 14:36