To help or assist someone with an action or task; to lend a hand (physically or mentally).
荷物が重かったので、友達に運ぶのを手伝ってもらった。
The luggage was heavy, so a friend helped me carry it.
明日のイベントの準備を手伝ってくれませんか？
Could you help me prepare for tomorrow's event?
料理が苦手なので、母に教えてもらいながら手伝った。
I'm not good at cooking, so I helped while my mother taught me.
To contribute to or be a factor in something's outcome or process; to play a part in making something happen.
毎日の運動が健康維持に手伝っていると思う。
I think daily exercise contributes to maintaining my health.
彼の早めの対応が被害の拡大を手伝った。
His quick response helped prevent the damage from spreading.