As an analogy, imagine a person coming from a foreign culture that also speaks English, but in their culture, ending a sentence with a dot is a sign of disrespect towards the recipient.
Note that in most IM conversations and texts, ending a message with a period makes one seem angry or insincere (see here).
That should depend on the rules of the language. My supervisor sometimes texted me with You will come (in Ukrainian) when we had not scheduled a meeting, I would rush in to see what got him, and find out he forgot the question mark (again).
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)
3. Open Threads should be posted in Discussion, and not Main.
4. Open Threads should start on Monday, and end on Sunday.