役に立つ, 便利な, 有益な
a useful tool
♔基本a useful tool
役に立つ道具
⦣ useful＋名詞.
a useful dictionary for students
a useful dictionary for students
学生にとって役に立つ辞書
A pocket knife is very useful on a camping trip.
♔基本A pocket knife is very useful on a camping trip.
ポケットナイフはキャンプ旅行ではとても役に立ちます.
⦣ be動詞 ＋ useful.
He is very useful in the kitchen; he is a good cook.
He is very useful in the kitchen; he is a good cook.
彼は台所ではとても役に立つ. 料理がうまいのだ.
She made herself useful around the house.
She made herself useful around the house.
彼女は（家で自分自身を役立つようにした）家事の手伝いをした.
⦣ make AB （形容詞）は「A を B （の状態）にする」.
A helicopter is sometimes more useful than an airplane.
A helicopter is sometimes more useful than an airplane.
ヘリコプターは時には飛行機よりも役に立つ.
A flashlight is one of the most useful things when camping.
A flashlight is one of the most useful things when camping.
キャンプでは懐中かいちゅう電灯は最も役に立つ物の1つだ.
