Ahh they're using the language barrier option. Repeating what you just said (sometimes with added volume) will somehow magically make the person understand you.

It doesn't always help doing the opposite thing though. Youngest (when more prone to tantrums than he is now) would often scream at me to just answer his question but couldn't understand that all the "random crap" I was spouting in the meantime was me taking a few goes to make him understand the answer.