Magic of English!

Professor Ernest Brennecke of Columbia is credited with inventing a
sentence that can be made to have eight different meanings by placing
ONE WORD in all possible positions in the sentence: "I hit him in the
eye yesterday."
 
The Query: What is this word?
 
The Answer: The word is "ONLY".

The Message:

1.       ONLY I hit him in the eye yesterday. (No one else did.)
2.       I ONLY hit him in the eye yesterday. (Did not slap him.)
3.       I hit ONLY him in the eye yesterday. (I did not hit others.)
4.       I hit him ONLY in the eye yesterday. (I did not hit outside the eye.)
5.       I hit him in ONLY the eye yesterday. (Not other organs.)
6.       I hit him in the ONLY eye yesterday. (He doesn't have another eye.)
7.       I hit him in the eye ONLY yesterday. (Not today.)
8.       I hit him in the eye yesterday ONLY. (Did not wait for today.)