1. I see a fly on my leg.
2. I saw a foreigner on the street.
3. I saw the foreigner on the street.
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In #1, 'on my leg' modifies 'a fly'? Am I right?
What about #2? Does 'on the street' modify 'a foreigner'? Or does 'on the street' modify the verb saw? What is the difference between these two sentences? What is the difference between #2 and #3? Does #3 mean that there was only one foreigner on the street?