Do USB-A adapters fit USB-C ports?

Yes, in most cases. There are adapters for a few euros that connect USB-A plugs to USB-C ports. However, there are some limitations.

What restrictions are there?

Some adapters are only suitable for charging devices. You have no contacts for data transfers. Other adapters allow data transfers, but only at a speed of 480 Mbit/s.

How fast are the data transfers with a good adapter?

Good adapters enable data transfers at a speed of 10 Gbit/s. This corresponds to the speed of USB 3.2 Gen 2.

Which adapters don't work with USB-C?

Pure Thunderbolt devices will not work on pure USB hosts. USB-C docks with display outputs also do not work as expected on USB-A hosts.

What problems can occur with adapters?

With adapters of poor quality, the connection can only work with a certain orientation of the USB-C plug. In addition, adapters can be an additional source of interference that can lead to disconnections. Finally, the USB-A device's power supply may not be sufficient to power the adapter.