a mitochondrion / many mitochrondia
a phenomenon / many phenomena
a criterion / many criteria

courtesy = politeness
intimidate (v.) = pelotella
intimidating  (adj.) = pelottava

(to) be wounded = haavoittua

verbejä joihin ei tule prepositiota:
attack s-b
join s-b
visit a place
influence s-b
affect s-g
impress s-b
mount e.g a bike
enter a room