The word "pertain" is correct and usable in written English. It is a verb which means "to relate to; be relevant to (a particular subject)." For example, you could say, "The professor discussed topics that pertained to the course.".
But it doesn't really pertain to me in my work thankfully.
It was no accident that she received the backing of rural west of Ireland and border county councils where these values still pertain.
An LBA spokesman said the widely reported "special regular medical examination" (SIC) mark on Lubitz's file could pertain to any medical problem.
Other nascent uses pertain to music festivals.
He referred to a longstanding anomaly, the so-called "West Lothian Question", by which Scottish MPs vote in Westminster on policies which do not pertain to Scots, because the issues concerned, for example health and education, have been devolved to their own parliament.
"The most important of these will pertain to an independent media and judiciary, and free and fair elections.
Among the best young mathematical brains, however, that equality does not pertain.
Awesome tool! I started using it one year ago and I never had to look for another app
Ha Thuy Vy
MA of Applied Linguistic, Maquarie University, Australia