選ぶ vs 決める
JLPT N4 vocabulary · what is the difference?
選ぶ is picking one item out of a set that is in front of you; 決める is settling a matter, and it does not need a set of options at all. You 選ぶ a colour from the colours on the menu, but you 決める the date of the trip, the rules, or your mind.
When to use each
選ぶ
えらぶ
Use 選ぶ when there is a set of candidates and you take one of them. If you can naturally add 〜の中から (from among ~), 選ぶ is the word.
この三つの中から一つ選んでください。
このみっつのなかからひとつえらんでください。
Please choose one from these three.
彼はクラスの代表に選ばれました。
かれはクラスのだいひょうにえらばれました。
He was chosen as the class representative.
決める
きめる
Use 決める when you fix or settle something — a date, a rule, a plan, an intention. There may be options behind the scenes, but 決める looks at the result, not at the choosing.
出発の日を決めましょう。
しゅっぱつのひをきめましょう。
Let's decide the departure date.
留学すると心に決めました。
りゅうがくするとこころにきめました。
I made up my mind to study abroad.
Sentences where only one works
メニューから好きなものを選んでください。
メニューからすきなものをえらんでください。
Please choose whatever you like from the menu.
The menu is the set of candidates, so 選ぶ. 決める would sound like you are being asked to settle the restaurant's policy.
会議の時間を決めてください。
かいぎのじかんをきめてください。
Please decide the time of the meeting.
No list of times is given; you are fixing one. 時間を選ぶ would only work if someone had already offered you two or three slots.
クラスのルールを決めます。
クラスのルールをきめます。
We will set the class rules.
Rules are created, not picked off a list, so 決める is the only option.
どの大学にするか、まだ決めていません。
どのだいがくにするか、まだきめていません。
I haven't decided which university yet.
Options do exist here, but the speaker is talking about not having settled it. 選んでいません would stress the act of picking and sounds odd as a general answer.
Common mistakes
明日の予定を選びます。
明日の予定を決めます。
A schedule is not a row of items you pick from; you fix it. 選ぶ needs candidates.
この二つの中から決めてください。
この二つの中から選んでください。
〜の中から names a set, so the verb has to be 選ぶ. Saying どちらにするか決めてください is fine, because the set is no longer stated as 〜の中から.
Frequently asked questions
Can both work in the same sentence?
Often yes, with a shift in focus. 大学を選びました means you picked one of several; 大学を決めました means it is now settled. Neither is wrong, but 決める is the natural answer to "have you decided yet?"
Which one do I use for ordering food?
Both are common. 何にするか決めた is the usual casual way to ask whether someone has decided, while 選ぶ shows up when the menu itself is the topic: メニューから選ぶ.
Is 選ぶ only for physical things?
No. You can 選ぶ a job, a word or a path, as long as the sentence implies there were alternatives.