Merging it with "ah" so "caught" sounds exactly like "cot" (fine in American, wrong in British).
Especially tricky for speakers of: Spanish, Hindi.
These two words differ by exactly one sound. Tap both — can you hear it?
Record yourself saying door, then compare with the target. Your audio stays on this device — nothing is uploaded.
Tap the speaker to hear each word; tap the word for its full pronunciation page.