We saw this sign at the front desk in our hotel on a recent trip to Luxembourg.

One thing the sign says is: ‘Please leave your room till 11:00 am.’ That says the opposite of what is intended:
- intended meaning: please leave your room permanently before 11:00 am.
- actual literal meaning: please leave your room temporarily now and don’t come back until11:00 am.
This is an error that many German speakers make when they speak English. Because German speakers are thinking of the German preposition bis, they often use until when they mean by. I have written about this before at Enter until 15 July – Language Miscellany
I assume the sign was written by a native German speaker, or perhaps by a native speaker of Lëtzebuergesch who had been heavily exposed to German throughout primary school. For more on languages in Luxembourg, please see Languages in Luxembourg – Language Miscellany
Looking at the online Lëtzebuergesch dictionary at „bis“ – LOD I see that bis also exists in Lëtzebuergesch. Nothing in that entry shows whether Lëtzebuergesch bis is used in the same ways as German bis, so I can’t tell what caused this hotel’s misuse of English: was it contamination from German, or contamination from Lëtzebuergesch?
I’ve always found it interesting to see what types of error people make in speaking (or writing) English they have learnt as a foreign language. Those errors often point to features that I might otherwise overlook in the speaker’s first language. How German speakers pronounce English – Language Miscellany