Expressions:
@(a|e|p|r|s)[\[<(.+)>\]] from %command sender%
[@]%object% from %command sender%

#Looping a Basic selector

command /example1:
    trigger:
        loop @a from command sender:
            send "Hi!" to loop-selected

#Basic selector

command /example2:
    trigger:
        send "Hi!" to @a from command sender

#Basic selector2

command /example3:
    trigger:
        send "Hi!" to @p from command sender

#Basic argument selector

command /example4 <text>:
    trigger:
        send "Hi!" to @arg 1 from command sender

#Looping a Basic selector and getting its location

command /example5:
    trigger:
        loop @e from command sender:
            set {_s} to loop-selected #Need to set to a var first bc of a bug
            send "%{_s}% %location of {_s}%" to @a from command sender

#Expressions in selectors
command /sendtoteam <text>:
    trigger:
        set {_selector} to "@a[team=%arg 1%]"
        send "Hi!" to @{_selector} from player

#Advanced selector

on right click on netherrack:
    send "Hello everybody close by!" to @a[distance=0..10] from player