Learn Hardcore Vietnamese: Tôi đã viết xong thiệp cho Lan rồi. - I have finished writing the card for Lan.

đã goes before the verb and marks the action as completed / in the past.
rồi often goes at the end of the sentence and adds the idea of already or the action is now done.

So Tôi đã viết xong thiệp cho Lan rồi sounds like:

Vietnamese often allows this kind of stacking. It may sound redundant if translated word-for-word into English, but it is natural in Vietnamese.

You could also hear shorter versions, such as:

Both are possible; the full version just emphasizes completion more clearly.

What does xong mean here?

xong means finished or completed.

After a verb, it works like a result complement, showing that the action has been brought to completion.

So:

This is a very common pattern in Vietnamese:

In this sentence, viết xong tells you not just that the person wrote, but that they finished writing.

Why is the word order viết xong thiệp and not ?