くらい

[Approximation: about / approximately]

Connection: Number/amount + くらい (or ぐらい — interchangeable)

Key uses:

1. Approximate amount: 10分くらい (about 10 minutes); 千円くらい (about 1000 yen)
2. Approximate time: 3時間ぐらいかかります (It takes about 3 hours)
3. Degree/extent: これくらい大きい (about this big)
4. "At least this much": 挨拶くらいできるでしょう (You can at least do greetings, right?)

くらい vs ぐらい: Completely interchangeable. ぐらい is slightly more casual.

くらい vs ごろ: くらい = approximate amount/duration; ごろ = approximate point in time.

• 10分くらい待ちました (I waited for about 10 minutes — duration)
• 3時ごろ来ます (I'll come around 3 o'clock — point in time)

Examples:

• ここから駅まで20分ぐらいです (It's about 20 minutes from here to the station)
• 何人くらい来ますか (About how many people will come?)
• このくらいでいいですか (Is about this much OK?)