If I lose my left AirPod will my right one still work ?

Hello mkx2020,

Yes, you can still use your left AirPod if you lost the right one. This article can help you locate or replace a missing AirPod: Find your lost AirPods - Apple Support

If you need to find only one AirPod or AirPod Pro

If your AirPods or AirPods Pro are separated from each other, you see only one location at a time on the map. Find the AirPod or AirPod Pro that you see on the map, and put it in its case. Then refresh the map and find the other one.

Replace a missing AirPod or charging case

If you still can't find your AirPod or charging case, or if something is damaged, get the serial numberand then contact Apple Support for a replacement. Then learn how to set up your replacement.

You can also learn more about AirPods pricing and service options.

Best Regards.