Alma wiki

• Safe mode : Shift after startup tone and until login screen
• Other boot disk (USB etc.) : Option ⌥ after startup tone and until startup choice appears
• Boot Recovery partition : Command ⌘+R
• Boot Recovery partition from network: Option ⌥+Command ⌘+R
• Verbose : Command ⌘+V
• Hardware test : D immediately, until test windows
• Reset PRAM/NVRAM : Option ⌥+Command ⌘+P+R, then release the keys after you hear the startup sound for a second time
• Reset SMC: press and hold the left Shift ⇧)+Control ⌃+Option ⌥ keys along with the Power (⎋) button, all at the same time, until the computer turns on. Now release the keys and then turn your Mac back on using the power button.<br/>

With a Windows keyboard:

• Command ⌘ is Win ⊞
• Option ⌥ is Alt

(From https://www.idownloadblog.com/2016/05/23/mac-startup-key-combinations/ see also: https://support.apple.com/en-us/HT201255)