The phrase 'drop litter' is correct and usable in written English. You can use it when you want to refer to someone leaving behind garbage or other refuse in a public area. For example, "People should not drop litter on the beach.".
Captain Clean asks everyone to join in with his anti-littering campaign, leads them through a rap ("Don't drop litter on the street/It looks a mess and sticks to your feet... ......) and hands out his "Keep it Clean" T-shirts.
Why do people drop litter in the first place?
People who drop litter really stress me out.
P.S. Do you think it would be possible to ask people not to drop litter?
Females may line forms with hair prior to giving birth, but some drop litters in existing depressions on the ground with no further preparation.
"I was angry about people dropping litter.
Under the SOCPA, a person can be arrested for any offence - even dropping litter.
Since I tried Ludwig back in 2017, I have been constantly using it in both editing and translation. Ever since, I suggest it to my translators at ProSciEditing.
Justyna Jupowicz-Kozak
CEO of Professional Science Editing for Scientists @ prosciediting.com