The easiest way to tell them apart is by their leaves. Wild garlic has hollow leaves and wild onion has solid flat leaves. Both are noticeable in lawns where they generally grow faster than the surrounding grass.
Control is the same for both species.
Integrated Pest Management Strategies 1. For isolated plants dig and remove all of the underground bulbs or replace the whole shovelful of soil with clean soil. Replant or resod the spots. Pulling the plants is not effective because many bulbs or bulblets are left underground where they continue to grow and multiply. Use chemical herbicides.