Usage patterns
〈動詞〉必要があるthere is a need to do <verb>
To solve this problem, we need to look into it more thoroughly.
〈物〉が必要になるX becomes necessary
The new project will require additional staff.
必要最小限の〈物〉the minimum necessary amount of X
I set off on the trip carrying only the bare minimum of luggage.
Expressions
必要ないunnecessary; not needed; not necessary 必要なしnot required; unnecessary; not needed