It always helps me to think of the English translation when trying to memorize and understand some the Cisco IOS settings I think are important.
Here are some Cisco IOS switchport configurations translated into English:
‘switchport mode trunk‘ says: “Always trunk on this end, and I will send DTP to attempt to negotiate a trunk on the other end.”
‘switchport nonegotiate‘ says: “Do not send or respond to DTP from this end. Disable all DTP on this port.” (Best used on user access ports, when trunking to non-Cisco switches, when trunking to a router1, or if you are paranoid about fast convergence2)