Radio button, checkbox or switch?

Radio buttons are best when only one option can be selected at a time from a set (for example choosing one preference or mode). Switches are best for communicating activation (e.g., turning a setting on or off). Checkboxes are best for communicating selection (e.g., selecting multiple items from a list).

When to use an emphasized radio button?

Emphasized radio buttons are optimal for forms, settings, and other scenarios where the radio buttons need to be noticed. Default radio buttons are optimal for application panels where all the visual components are monochrome in order to direct focus to the canvas.

No partial state

Radio buttons can only be on or off. Indeterminate radio buttons don't exist in accessibility APIs, so it's not possible to make an indeterminate radio button accessible. If you need to show a partial state, use a checkbox instead of a radio button. When a parent radio button represents a group of radio buttons, it should be turned off unless all of the radio buttons are on (turning the parent radio button on turns all of the radio buttons on).