Difference of exercise, drill, practice, rehearse, train
日本語の「練習」に訳されることのある英単語（exercise, drill, practice, rehearse, train）の違いをまとめた。
LONGMANの英英辞典で，これらの単語の意味を調べ，それぞれのイメージを把握して使い分けを考えた。各単語の英英辞典の記載内容を引用し，それぞれのイメージを説明しまとめた。なお，英語は動詞がメインの言語であるので，英英辞典は動詞の意味を参照した。
exercise
1 use something [transitive] formal to use a power, right, or quality that you have
2 do physical activity [intransitive] to do sports or physical activities in order to stay healthy and become stronger
3 use part of your body [transitive] to make a particular part of your body move in order to make it stronger
4 animal [transitive] to make an animal walk or run in order to keep it healthy and strong
5 make somebody think [transitive] formal
a) to make someone think about a subject or problem and consider how to deal with it
b) British English if something exercises someone, they think about it all the time and are very anxious or worried – often used humorously
身体的な動きを伴うイメージ。スポーツや楽器の練習の意味に適している。
drill
1 [intransitive, transitive] to make a hole in something using a drill
2 [transitive] to teach students, sports players etc by making them repeat the same lesson, exercise etc many times
3 [transitive] to train soldiers to march or perform other military actions
4 [transitive] to plant seeds in rows using a machine
学生やスポーツ選手などの集団に，教えたり，何回も反復させること。学校での課題演習など，反復練習の意味で使うのに適している。
practise/practice
イギリス英語ではpractiseをpracticeの動詞として使う。アメリカ英語は同じ。
1 [intransitive, transitive] to do an activity, often regularly, in order to improve your skill or to prepare for a test
2 [transitive] to use a particular method or custom
3 [intransitive, transitive] to work as a doctor or lawyer
4 [transitive] if you practise a religion, system of ideas etc, you live your life according to its rules
5 → practise what you preach
技能向上の目的のための活動。一般的な練習のイメージ。
rehearse
1 [intransitive, transitive] to practise or make people practise something such as a play or concert in order to prepare for a public performance
2 [transitive] to practise something that you plan to say to someone
3 [transitive] formal to repeat an opinion that has often been expressed before
何かの準備のために行うイメージ。演劇，コンサート，ショーなどの公開発表の練習の意味に適している。説明の中に，practiseの単語があるように，practiceの特殊なケース。
train
1 teach somebody [intransitive, transitive] to teach someone the skills of a particular job or activity, or to be taught these skills → training
2 teach an animal [transitive] to teach an animal to do something or to behave correctly
3 prepare for sport [intransitive, transitive] to prepare for a sports event or tell someone how to prepare for it, especially by exercising → training
4 aim something [transitive] to aim something such as a gun or camera at someone or something
5 develop something [transitive] to develop and improve a natural ability or quality
6 plant [transitive] to make a plant grow in a particular direction by bending, cutting, or tying it
指導（教える，教わる）が入るイメージ。exerciseに指導が入った場合もこれになる。いわゆるダンベルなどの（指導員のつかない）自主トレーニングはexerciseであり，部活動など監督者のいる運動はtrainになると思われる。
Summary
ここまでの英単語のイメージを以下の表にまとめた。
| Word | Image |
|---|---|
| exercise | 身体的な運動を伴うもの |
| drill | 集団への反復が伴うもの |
| practice | 技能向上のためのもの |
| rehearse | 準備として行うもの |
| train | 指導が入るもの |
個人的なイメージとしては，practiceが最上位に位置し，その他の単語はpracticeの特殊な事例のように感じた。
プログラミングや語学学習や資格試験のための「練習」はpracticeで問題ないように思った。
