In Chinese writing there are usually two parts or ‘radicals’ in a character, a semantic (meaning) and a phonetic (sound) radical. If there is a phonetic part, that corresponds to the spoken word, which has a meaning, why would you need a semantic part? There are many homophones in Chinese – words that sound the same but have different meanings. In speech this might be ok, as the specific meaning may be determined by the context of what you are talking about or where you are, or what you are doing, and if there is any confusion you can ask for clarification. But what if you want to just write a short message? One of the main things about writing is that the author is not present, it can be read without them. Writing can also be taken out of its context – the message may appear at any place and time. So the unspoken semantic radical is required to disambiguate the meaning.