do you think english is not precise enough?
Sometimes It's hard to distinguish the pronounces "can" and "can't". And for example,"english" has two means ,people from England,and english language,sentence like that ''I love english" will make someone confused.
Comments
In US English, "can" and "can't" are quite difficult to distinguish for non-native speakers. The difference is that "can't" ends with a nasal stop - a slightly more abrupt ending to the sound - than "can". See this video: How to Pronounce Can vs. Can't -- American English Accent http://www.youtube.com/watch?v=Vp7xmbtylqI
There's no issue with your "English" example. As others have said, you always use an article - "the English" - when talking about the people.
The pronunciations of can and can't are easily distinguishable to native speakers, as are those of ten and ten and wan and want, etc. "Pronounce" is a verb, not a noun. Any language is difficult to understand when you are learning it.
"I love English" can only refer to the language. If you are referring to the people you say "I love the English." Many similar problems can be resolved by knowledge of English, and sometimes by knowledge of the English.
It's very complexity, flexibility, and way English has borrowed words from many other languages, plus the multitude of slang terms, proverbs and expressions which are said in regular speech (many of which don't actually mean what a non English speaker would think they mean) is the charm and beauty of it.
In your example, English would mean the language, but "the English" would mean the people. there is usually a way to be more specific. \in speaking emphasis is used, or the contraction can be avoided. Can not is harder to mistake for can.
It's true, there are quite a few short forms! But I do understand what you mean by the 'I love english'