yes, all old words are in complete relationship to each other. the sounds that the characters make can infer to the reason that the word ends up making a meaning. some are rather silly, like it could be thought that the direction that air is push for gadol and katan makes them defined the way they are, as they are opposing movements to create the sounds.
Why is in "the" tower wrong? I thought a word beginning with ב could be either "a" or "the".
I think I get it now... the pronunciation of tower sounds like "be", not "ba", and "ba" would indicate "the", whereas "be" indicates "a".