Dialogues

What goes through the minds of the people who write language-teaching books? Here is a dialogue from my textbook. It is between, I assume, Oscar Wilde and a particularly patient shop assistant.

Assistant: 'Who's next?'
Customer: 'I am next.'
Wilde: 'No, I was before you.'
Customer: 'Pardon me.'
Assistant: 'What can I get you?'
Wilde: 'I would like ten beautiful roses.'
Assistant: 'Would you like yellow roses or pink ones?'
Wilde: 'I would like neither... perhaps you have some red ones?'
Assistant: 'Alas, no.'
Wilde: 'All right, I'll take five yellow and five pink. How much does one rose cost?'
Assistant: 'One hundred and seventy-five crowns.'
Wilde: 'Aie, I have no money. May I pay you tomorrow?'

The indigent aesthete, famously the best teaching-aid. Or else we are expected to believe that the characters are educationally subnormal:

Troll 1 [trying to trick his friend]: 'What day is today?'
Troll 2 [firmly]: 'Today is Tuesday.'
Troll 1 [wheedling]: 'Isn't today Wednesday?'
Troll 2 [counting on his knuckles]: 'Hmm, you're right.'
Troll 1 [triumphant]: 'Yes, yesterday was Tuesday.'
Troll 2 [desperate to win back some troll-cred]: 'And it's Thursday tomorrow.'

But now I know the days of the week. Saturday - Laugardagur - must have some connection with 'lauga', 'to wash'.