Back then, I was taught that the apostrophe is to be used in the following cases:

1. Show ownership e.g. Dida's wife

2. Contraction of phrases e.g. must not=mustn't, is not= isn't.

3. Names of people like Ng'ang'a and Okot p'Bitek.

What we see these days:

Plural:

Wazuan's please advise.
No matatu's beyond this point.

Plural for abbreviations:
100 MP's to accompany Ruto.

Plural for family members referred to collectively:


The Odinga's have been a force to reckon with in Kenyan politics.

The Katana's visited us last Sunday.

Plural for years in one decade:

The 1990's were tough for Kenya.

Let's avoid misusing/overusing the apostrophe!

...and commas. Like in ",Essential Contact",

...Wonder what was in the mind of this 'threader'!!!

I see this quite often and wonder!

shows plural possession. Check these example... The children's cows.

or many guys called Dida having one wife

It is correct if the name is Didas and not Dida.

informally if you meet two guys called Kamau (john kamau and joseph kamau) or a family whose surname is Kamau. you will not be wrong to refer to them as 'Kamaus' or 'the Kamaus' - sio? if this premise is correct then it follows that if we are referring to a polyandrous woman who has a fetish for dudes named Dida (John Dida and Joseph Dida).
in a sentence...

you will be correct!

in that case it will be Didases wife

And Exclamation marks. E.g.

Ok!!!!!!!