He asked a few pertinent questions.

Technically, you're right. However, you must also consider the unusual circumstances that pertain here.

Yanni is perturbed about Skura's lesbian relationship with Nuja.

‘Creole’ means pertaining to people who are descended from a mixed European and African background, especially in the Caribbean islands, and their culture and cuisine, or the languages of these people or of others.

That's a very pertinent question.

A reward has been offered for information pertaining to the incident.

It isn't pertinent.

That's not pertinent.

Sami is perturbed about that.

This discussion does not pertain to you.