"Are you guys coming back today?" is the Engpsh translation of "你们今天回来吗?"

The sentence is made up of several grammatical elements. "Are you guys" is the present tense of the verb "to be," and it is used to ask a question. "Coming back" is the present participle form of the verb "to come back," which means to return to a place where one has previously been. "Today" is an adverb that specifies the time frame in which the action is taking place.

Here are some example sentences using similar grammatical structures:

"Is he coming to the party tonight?" (他今晚会来参加聚会吗？)
"Are they going to the store tomorrow?" (他们明天会去商店吗？)
"Will you be attending the meeting next week?" (你下周会参加会议吗？)