How do you create a vertical. not loop cut but say you have a model of a face and you need a vertical line along the nose…what buttn you push for this like you would draw a straight line with a pencil?

Please help or post a video to show and if no one knows what im talking about i can put a link to a youtube video that show a guy doing it with his head model.

select the edges you want to cut, then press ‘k’ and select ‘knife (exact)’, then click where you want to start and click again where you want to stop to create a straight line (or click and hold down the mousebutton to draw the line you want). You can also use Ctrl when clicking to snap to vertices

Alright thanks, names not really what i am i just like having newbie in my name so people dont expect much lol. But i have fixed out the loop cut/face tool and such but could figure the knife one out so thanks alot.