❶（～と）考える, （～だと）思う
I think so.
♔基本I think so.
私はそう思います.
⦣ think＋副詞.
I don't think so.
I don't think so.
私はそうは思いません, 私はそうではないと思います.
I think (that) Ken is nice.=Ken is nice, I think.
♔基本I think (that) Ken is nice.=Ken is nice, I think.
私はケンはすてきだと思う.
⦣ think＋that節. that はしばしば省略される.
He thinks he is right.
He thinks he is right.
彼は自分（の言うこと）が正しいと思っている.
I don't think Ken will come today.
I don't think Ken will come today.
私はきょうケンは来ないと思う.
✓POINT
「～しないと思う」は英語ではふつう, 「～するとは思わない」のようにいう（英文では先に否定形をいう）.
Do you think this is a monster?—No, I don't think so.—Then, what do you think this is?—I think it's a kind of shark.
会話Do you think this is a monster?—No, I don't think so.—Then, what do you think this is?—I think it's a kind of shark.
君はこれが怪獣かいじゅうだと思うか.—いや, そうは思わない.—ではこれは何だと思う?—サメの一種だと思う.
文法 ちょっとくわしく
「これは何だ」は What is this?What＋動詞＋主語.
「これは何だと思うか」は What do you think this is?
⦣ What の次に do you think を挿入そうにゅうすると, is this は this is （主語＋動詞）になる.
Where do you think she lives?
Where do you think she lives?
彼女はどこに住んでいると思いますか.
✓POINT
「彼女はどこに住んでいるか」は Where does she live?. do you think （思うか）を入れると上文のようになる.
"Ken is nice, " she thought.
“Ken is nice, ” she thought.
「ケンってすてき」と彼女は思った.
She thought (that) Ken was nice.
She thought (that) Ken was nice.
彼女はケンがすてきだと思った.
⦣ 主節の動詞 （thought） が過去なのでそれに合わせて that 以下の動詞も過去 （was） にする. ×「ケンがすてきだったと思った」と訳さない.
He thought and thought, and at last he made up his mind to do it.
He thought and thought, and at last he made up his mind to do it.
彼はいろいろ考えたあげく, ついにそれをしようと決心した.
⦣ ～ and ～ は「反復または強意」を表す.
I was thinking that the plan would go well.
I was thinking that the plan would go well.
その計画はうまくいくと思っていました.
⦣ think の意味を強調する形の過去進行形の文. was助動❶
❷（いろいろと頭を使って）考える
think carefully [hard]
think carefully [hard]
注意深く[一生懸命けんめいに]考える
think about the question
think about the question
その問題について考える
May Jimmy come to our party?—I'll think about it.
会話May Jimmy come to our party?—I'll think about it.
ジミーも私たちのパーティーに来ても[呼んでも]いい?—（そのことについては）考えておこう.
⦣ 断る時の遠回しな言い方.
Ann is thinking about Ken all the time.
Ann is thinking about Ken all the time.
アンはいつもケンのことばかり考えています.
⦣ think の意味を強調する現在進行形.
He did it without thinking.
He did it without thinking.
彼は考えないでそれをやった.
⦣ 前置詞＋動名詞 thinking （考えること）.
