Adverb + 久
久 (jiǔ) is an adjective meaning "long" in terms of duration or time. It is often used with adverbs like 最 (most) or 很 (very) and appears in expressions describing how long something has lasted.
好久不见,你最近怎么样?
hǎo jiǔ bú jiàn, nǐ zuìjìn zěnmeyàng?
Long time no see, how have you been lately?
这件事已经过了很久了,别再想了。
zhè jiàn shì yǐjīng guò le hěn jiǔ le, bié zài xiǎng le.
This matter happened a long time ago, stop thinking about it.
他在国外住了很久,中文说得没以前好了。
tā zài guówài zhù le hěn jiǔ, zhōngwén shuō de méi yǐqián hǎo le.
He lived abroad for a long time, and his Chinese isn't as good as before.