What's the difference between 2 sentences?

Question

Dem Karl verdanke ich viel.

and

Ich habe Karl viel zu verdanken.

They both mean "I owe a lot to karl" but are they exactly same?

Answer 1

The meaning is very similar, if not outright the same. But the "mechanics", so to speak, the way to grammatically get there, is a bit different. Maybe it's helpful to look at more literal translations for both sentences:

Ich verdanke dem Karl viel. (in a more standard word order)
I owe a lot to Karl.

Ich habe dem Karl viel zu verdanken.
I have a lot to thank Karl for.

Answer 2

At first reading they mean basically the same.

Maybe a slight difference in at least what I feel after reading the sentences carefully is:

• the first sentence is more an act in the past that is ended and I'm still aware of my thankfulness
• in the second I feel something, that I'm still in his debt

But this is only a feeling after I was trying to feel a slight difference. Correct me if I'm mistaken.