Barriers of communication. Does it exists?

Just now while i was in the lift, i nearly giggled. Why?

Cause there were these two malay people, one male one female. The gentleman was talking in English, i would conclude that he has a good English background and would be able to speak fluent English. As for the other lady, she was speaking in Malay (Bahasa). We Malaysian do realise that we have multiple language that we can use, but these two person was talking in dfferent language on the same conversation. The gentleman kept talking in English meanwhile the lady was replying and communicating in Malay, this kept going on for few minutes while in the lift. It amazes me as this we would consider as 'Chicken and Duck Talk'. Haha...