 Consider the two sentences John finds a unicorn and John seeks a unicorn. These are syntactically alike (subject-verb-object), but are semantically very different. From the first sentence follows that there exists at least one unicorn, whereas the second sentence is ambiguous between the so called de dicto (or non-specific, or notional) reading which does not imply the existence of unicorns, and the de re (or specific, or objectual) reading from which existence of unicorns follows.