虚词"当然":empty word "of course"

The Chinese empty word (虚词) "当然" is generally translated as "of course" or "certainly". It makes perfect sense in this example, "你会游泳?", "[我]当然[会] ("You can swim?", "Of course [I can]"). But "当然" is also commonly used in a different context, as in "明天每个人都必须到办公室，当然你事先请假了可以不来"("Everybody must come to office tomorrow. But of course you don't have to come if you asked for leave earlier"). In this case, "当然" is said in a much weaker tone and more resembles "but", "nevertheless", "however" in meaning than the more common "of course". The German "natürlich" ("naturally") or "allerdings" ("though") may be closer to this sense. English does have this meaning, as Wiktionary says "Acknowledges the validity of the associated phrase", e.g. "Of course, there will be a few problems along the way". But this sense is used more often in Chinese.