conundrum

[Brendan Mulachy]

what has 4 letters, sometimes has 9 letters but never has 5 letters

 

[Cobra]

what has 4 letters, sometimes has 9 letters but never has 5 letters ?

Spoiler

Yes you are quite correct

 

[viv1969]

You are correct indeed....except for the question mark.

 

[kendo1]

... and almost has 6 letters, possibly has 8.

 

[Nod]

Not 3.

 

[Nod]

But 3.

 

[Byker28i]

maybe 5 and definitely 10

 

[viv1969]

Forever seven.
Indefinitely twelve.

 

[SarahLee]

always 6 but occasionally 12.

 

[AJQS]

A superstitious post man?