が必要 => need; necessary N4
必要がある => Need/Need to N4
[必要「ひつよう」]はない => It is not necessary for A to be done N2
Needs, Requirements
間 => while; during; between ~ N4
的 => about (change noun into na-adjective or adverb) N3
瞬間 => At the very moment N3
Short period of time
間に => while; during~ something happened N4
[時「とき」] => At the time A N5
Time
と同時に => at the same time as; while; simultaneously ~ N2
[間「あいだ」]/[間「あいだ」]に => During A, During A (before A is finished/over) N2
Time, Situation
Vた[時「とき」] => After having done something N5
Time
必ずしも~とは限らない => Not necessarily; not always N3