The alkyne series is very similar to the alkane and alkene
series. They all have at least one triple bond. Please note the fact
that a single letter change results in a dramatic change in the
structure of a compound. 
Alkyne Formula Ethyne C_{2}H_{2 }Propyne C_{3}H_{4} 
And the pattern continues just as it did for the alkanes
and alkenes. The general formula of an alkyne is C_{n}H_{2n2}.
The triple
bond prevents rotation but it also prevents the formation if cis and
trans
structures in the parent chain. 
In the event a parent chain has both an alkyne and an
alkene the alkyne
is more important. 
example

8 carbons long therefore an "oct". Has both alkene and an
alkyne bonds.
The alkyne is the most important therefore number so that it has the
lowest
possible number. Therefore we now have "3yne" and an alkene at 5 and
at
7. Therefore the full name would be oct5,7diene3yne. 
All the other rules previously learned still apply. 