First "that crab eats the mouse" now this! What happened to ciasteczka?
Would "I see someone at home" work as well?
Yes, it works.
I see someone is home.
Does this work, or is there another way you'd say this?
I believe there's an implied conjunction here: 'I see (that) someone is home' = Widzę, że ktoś jest w domu.
Jaka jest różnica między "ktoś" i "kogoś?"
he sees me
I see him
ktoś is nominative case.
kogoś is accusative case.
Why is "I see someone in a house" incorrect?
Automatically one assumes that it's some specific house, but unspecified "a house" should be okay as well. Added.
I see somebody in the home. Marked incorrect?
Okay, added now.
Either a burglar or a mistress.
Is "I see someone in my house" a likely meaning of this sentence?
How about: I (can) see someone inside the house
Should "I see someone at the house" also be accepted?
I see someone is at home
"Widzę, że ktoś jest w domu".