気(き)を使(つか)うto pay attention to another's needs, to attend to, to fuss about, to take into consideration

上司(じょうし)：「職場(しょくば)では言葉(ことば)に気(き)を使(つか)いなさい。」

Boss: "Be mindful of your language at work." {to pay attention to another's needs, to attend to, to fuss about, to take into consideration}

客(きゃく)：「どうぞ、私(わたし)に気(き)を使(つか)わないでください！」

Guest: "Please, don't fuss about me!" {to pay attention to another's needs, to attend to, to fuss about, to take into consideration}

いつもお洒落(しゃれ)な同僚(どうりょう)の武田(たけだ)は常(つね)に身(み)なりに気(き)を使(つか)っている。

My always stylish colleague, Takeda, is always attentive to his appearance. {to pay attention to another's needs, to attend to, to fuss about, to take into consideration}

よそでは気(き)を使(つか)う事(こと)が多(おお)いので、私(わたし)は家(いえ)で一人(ひとり)でいるのが一番(いちばん)好(す)きです。

Since I often have to take into consideration others' needs when I'm outside, I like being alone at home the best. {to pay attention to another's needs, to attend to, to fuss about, to take into consideration}

上司(じょうし)には気(き)を使(つか)わないといけないので、上司(じょうし)と一緒(いっしょ)にいると疲(つか)れてしまいます。

Since I have to pay attention to my boss's needs, I get tired when I'm with my boss. {to pay attention to another's needs, to attend to, to fuss about, to take into consideration}