2.52-Ellipsis: Yup, just me
Reason: He did not have to say the full sentence.
4.13-Discourse marker: There are seats available on the Qantas airways flight but there is a three hour stop over in Singapore.
Reason: The lady is changing the subject from Qantas airways to the three hour stop over in Singapore.
4.51-Tags: They are three hours ahead, aren't they?
Reason: He is asking if the time is three hours ahead.
Done by: Vanshiqa and Bhakti