once
adverb
adverb
concern
noun
verb
-
concern, concerning, concerns, concerned
noun
verb
-
concern, concerning, concerns, concerned
noun
concept
noun
β’
The concept of time travel fascinates many scientists.
noun
concerned
adjective
adjective
verb
concentration
noun
noun
noun
noun
concentrate
verb
-
concentrate, concentrating, concentrates, concentrated
β’
I canβt concentrate with the television blaring in the background.
verb
-
concentrate, concentrating, concentrates, concentrated
verb
-
concentrate, concentrating, concentrates, concentrated
noun
noun
concerning
preposition
adjective
