くらい (kurai) and ぐらい (gurai) are both used to indicate approximate numbers or amounts. They can be used in a variety of situations to express approximate numbers or amounts, such as the length, size, or price of something.
To use these words, you can simply add them after a number or quantity.
For example:
二十歳ぐらいの人 (nijū-sai gurai no hito – a person who is about 20 years old)
五千円ぐらいの服 (gosen-en gurai no fuku – clothes that cost about 5000 yen)
三メートルぐらいの長さ (san mētoru gurai no nagasa – a length of about 3 meters)
You can also use these words with nouns that express approximate numbers or amounts. For example:
十人くらいのグループ (jū-nin kurai no gurūpu – a group of about 10 people)
五十冊ぐらいの本 (gojū-satsu gurai no hon – about 50 books)
三十分ぐらいの時間 (sanjū-fun gurai no jikan – about 30 minutes)
Note that the form くらい (kurai) is used more commonly with numbers that end in 1, 3, 4, 6, 7, 8, or 9,
while the form ぐらい (gurai) is used more commonly with numbers that end in 0 or 2. However, either form can be used with any number.
Form
Verb (casual form) くらい
Noun ぐらい
な-adjective + な
い-adjective
Here are five example sentences using these words:
1.この本は五十ページくらいあります。(Kono hon wa gojū-pēji kurai arimasu. – This book is about 50 pages.)
2.この料理は二千円ぐらいするでしょう。(Kono ryōri wa ni-sen-en gurai suru deshō. – This dish will cost about 2000 yen.)
3.彼は一つぐらい買ってもいいですか？(Kare wa hitotsu gurai katte mo ii desu ka? – Can he buy about one?)
4.公園には三十本ぐらいの木があります。(Kōen ni wa sanjū-hon gurai no ki ga arimasu. – There are about 30 trees in the park.)
5.この部屋は二十平方メートルぐらいです。(Kono heya wa nijū-hekuta mētoru gurai desu. – This room is about 20 square meters.)