actual
The German word 'tatsächlich' is used to express the concept of 'actual' or 'in fact'. It is an adverb and is often used to emphasize a statement or to express surprise. For example, 'Tatsächlich ist es wahr' means 'It is actually true'.
I am actually very tired.
In this phrase, 'tatsächlich' is used as an adverb to emphasize the fact that the speaker is very tired. It could be used to contradict someone else's statement or assumption that the speaker is not tired.
He is actually the director of this company.
Here, 'tatsächlich' is used to stress on the reality that he, indeed, is the director of the company. The speaker might use this phrase to convince someone who doubts the director's position or identity.
That is actually a good idea.
In this case, 'tatsächlich' is used to express surprise at the fact that something is a good idea. The speaker was perhaps not expecting the idea to be good and is surprised to find that it is.