adverb
directly; head-on; right in front
Describes facing something squarely, without avoidance; often used with verbs like 向き合う, 受ける, ぶつかる.
See also: まとも
彼はまともに私の目を見て話した。
He spoke looking me straight in the eye.
台風がまともにこの地域を襲った。
The typhoon hit this area head-on.
adverb
properly; normally; in a normal way
Used when something is done in a proper, expected, or normal manner; often appears in negative sentences like まともに～ない.
風邪でまともに声が出ない。
I can't speak properly because of a cold.
彼はまともに仕事ができない。
He can't do his job properly.
adverb
Implies taking something seriously, dealing with it honestly, or in a fair/decent manner; often used with verbs like 取り合う, 相手にする, 考える.
彼の冗談をまともに受け取ってはいけない。
You shouldn't take his jokes seriously.
まともに考えれば、その計画は
If you think about it seriously, you'll see that plan is impossible.