English is an awful language. It's filled with ambiguity and confusion that can only be sorted by tone and context. Pay attention the next time you read a book or something with dialog. And then there are words that are constantly mixed up because they sound too alike. How many times have you gone through the following dialog:

Person A: blah blah blah blah in 15 minutes.
Person B: In 50 minutes??
Person A: FIFTEEN. One-Five.

It's sillyness.