What you're doing sounds perfect. My DD (19 months) seems to love to be quizzed. She doesn't talk, but she likes to point things out and have me ask her 'where is the triangle', etc.
I just keep doing it through play. She brings me books and I know she wants me to identify things for her or quiz her or whatever. She likes to point at the letters and have me tell her what they are.
At this age, I think play is the most important way to help learn. You can do tons of things from pinterest if you're wanting to push it further. Squishy bags where you draw shapes and letters with your finger, etc.
SAHM to Magnolia May (09/10), Luke Russett (04/13) and expecting 11/16. Wife and best friend to my airman.