As a non-native speaker I say that there is a huge difference between speaking/writing fluent English and doing this in a way that satisfies "unwritten cultural conventions".
For my English, for example, native speakers tend to say that it is actually quite correct, but I have a tendency to use words in a specific way in which few native speaker would use them.
For my English, for example, native speakers tend to say that it is actually quite correct, but I have a tendency to use words in a specific way in which few native speaker would use them.