[dylan604]

English doesn't need words with evil twins. English is much more cunning than that in that the same word can have totally opposite meanings. They tend to be more slang usage, but for example "shit". Without recreating the George Carlin bit, there's so many different meanings depending on how it is used.

[wolverine876]

Word meanings evolve many ways. Sometimes two word forms evolve independently and coincidentally to the same outcome. Sometimes a word develops from Latin or Greek, and then centuries later someone coins a different word from the same Latin or Greek. Sometimes people apply old words to new situations. Etc. If you look up the field of etymology, you can find many models of how words form.