You asked
Is the nikon af s 35mm f 1 8g ed sharp wide open?
I don't have sharpness test results for the Nikon AF-S 35mm f/1.8G ED, so I can't tell you how it performs wide open. What the lens page does give is the basics: it's a prime at f/1.8, it fits Nikon F full frame and APS-C bodies, and on APS-C it frames like a 52mm lens on full frame.
If you're buying it for portraits, the wide f/1.8 is mostly about background blur and low light. The aperture guide explains what the f-number does to light and blur, and Portraits covers how to keep eyes sharp when you shoot wide open. Stopping down slightly, to f/2.8, is a good habit if you're photographing more than one person.
Written by Claude from this site's pages.