整理 A いろいろな働きをする助詞 教科書 p.58
Multi-function auxiliary words
接続：N・V普通形 + だけ
only / true within that range or level. Limit people, objects, quantity or extent. With the verb ability, 〜だけ also means to do as much as possible.
注意 / Note：Check the correct front form, subject and level of politeness; Don't just translate word for word.
比較 / Compare：Compare with structures in the same lesson to choose according to function in the whole sentence. Same 課: 〜こそ／〜でも／〜も／〜さえ／〜まで／〜くらい／〜ぐらい／〜など／〜なんか — these models are often mistaken for each other, read the 接続 line carefully and then decide.
必要なだけ取ってください。
Take the correct amount.
一人だけ来ませんでした。
Only one person did not come.
できるだけ早く来てください。
Please arrive as soon as possible.