真(zhēn)
When adverbs 真 and 太 are used in exclamatory sentences, they convey in most cases not new factual information but the speaker's approval, disapproval, etc. If the speaker wants to make a more "objective" statement or description, other intensifiers such as 很 or 特别 are often used in place of 真 and 太.
Ex) 他睡觉真晚。
Ex) 他睡觉真晚。