"There was a knife on the table."
Translation:Na stole ležel nůž.
You are free to translate just "byl na stole".
It is much more common to say that the knife was on the table in English. And the other is much more common in Czech. That is the reason for difference in the translations.
The Czech national corpus has 93% of "ležel na stole" and only 7% of "byl na stole".
Engish ngrams has 5x to 6x more "was on the table" vs. "was lying on the table"
In our opinion, it is useful to show the difference.
Is it possible to translate this as "THE knife was lying on the table," without a demonstrative in the Czech sentence? For example...
Detective: "Where was the victim found" / Police Officer: "He was slumped over his desk in the study, with several apparent knife wounds." / Detective: "And did you see the knife?" / Police Officer: "Yes, the knife was lying on the desk. You can't see it from out here in the hall because the body is blocking the view."