〜くらい / 〜ぐらい
About / to the extent 〜くらい
Meaning
An approximate amount — "about ~" — or a degree — "to the extent that ~".
Formation
[quantity] + くらい · [plain form] + くらい
Notes
くらい and ぐらい are interchangeable. With a quantity it is "about": 三十分ぐらい. With a clause it gives a yardstick: 歩けないくらい疲れた ("so tired I couldn't walk"). For time or a starting point use ごろ instead: 三時ごろ ("around three o'clock") — ごろ is for points in time, ぐらい for amounts.
Examples
駅（えき）まで歩（ある）いて十分（じゅうぶん）ぐらいかかります。
It takes about ten minutes on foot to the station.
Breakdown
歩（ある）けないくらい疲（つか）れました。
I was so tired I couldn't walk.
Breakdown
三（さん）時（じ）ごろ、駅（えき）で会（あ）いましょう。
Let's meet at the station around three. (a point in time takes ごろ)
Breakdown
毎日（まいにち）一時間（いちじかん）ぐらい日本語（にほんご）を勉強（べんきょう）しています。
I study Japanese for about an hour every day.
Breakdown
この漢字（かんじ）ぐらい読（よ）めますよ。
I can at least read a kanji this simple.
Breakdown
⚠️ Often confused with
〜ば〜ほど
The more … the more 〜ば〜ほど
"The more ~, the more ~" — one thing increases as another does.
〜ほど / 〜ほどだ
To the extent 〜ほど
Gives a yardstick for how much — "so ~ that …", "to the extent of ~".
〜さえ / 〜でさえ
Even 〜さえ
Picks an extreme example — "even ~". If this much is true, the rest follows.
〜こそ
Precisely 〜こそ
Singles something out for emphasis — "this is the one that ~", "precisely ~".
〜てまで / 〜までして
Even going so far as 〜てまで
"Even going so far as to ~".
〜極まりない
Utterly extreme 〜極まりない
"Extremely ~", "~ in the extreme" — an emphatic, usually critical judgement.
〜といったらない
Beyond description 〜といったらない
"Indescribably ~", "~ beyond words" — an exclamation of extremity.
〜始末だ
Ending up badly 〜始末だ
"It ended up ~ (of all things)" — a bad process reaches a worse conclusion.