Shirabe
必ず しも

必ずかならず

Common Adverb
English jmdict
1
adverb (fukushi) always;without exception;necessarily;certainly;without fail;positively;invariably
あの歌は必ずヒットするよ。
That song's bound to be a hit.
English jmdict
1
adverb (fukushi) (not) always;(not) necessarily;(not) entirely;(not) all
with neg. sentence
金持ちが必ずしも幸福とは限らない。
The rich are not always happy.