[Mediterraneo10]

There are countries where either persisting in the local language or asking nicely, will meet with a negative response. Take the Netherlands, for example, where 90% of the population is said to speak English now. A foreign novice–intermediate learner trying to practice Dutch in everyday situations is likely to be told “Let’s just speak English and not waste time.” Your attempting to persist with your less-than-fluent command of the local language is interpreted by your interlocutor as disrespect for his time. If you want to learn the local language, you are expected to place the burden on your language teacher, not random shopkeepers etc.

[pacaro]

Agreed, it’s definitely context dependent. There’s a world of difference between holding up a line in a store and having a conversation, however limited, with a taxi driver.

[Mediterraneo10]

The shop could be completely empty, no queue, and the shopkeeper might be free and even bored, but chances are he still won't want to listen to a novice-intermediate foreigner practicing Dutch. Listening to halting speech can feel like a waste of your time even if you have nothing better to do.