A stammerer is a person who stammers — that is, someone who speaks with breaks and repeated sounds, like "I-I-I w-want to go." The sounds get stuck, or a word will not come out at all, and there is a pause in a place where you would not expect one. There are two reasons this happens, and they feel very different. Some people have a speech condition they have had since they were small; that is a lifelong thing and has nothing to do with being clever or nervous. Other people stammer only in one moment — because they are frightened, or shocked, or in love, or standing in front of a hundred people. English uses the same word for both, though "stammerer" as a label for a person is mostly used about the first kind. Now, the important part. "Stammerer" is a rather old-fashioned word, and many people today feel uncomfortable with it, because naming someone by the difficulty makes the difficulty into the whole person. Modern English much prefers "a person who stammers" or "someone with a stammer". You will meet "stammerer" in older books and in history writing — King George VI of Britain is often called one — but if you are talking about a real person in front of you, choose the longer phrase. Your listener will notice, and think well of you. One more thing: British English says stammer, American English usually says stutter, and they mean the same thing. So an American book will say "stutterer" where a British one says "stammerer". Neither is wrong; they are just two countries' habits.

口吃的人；會結巴的人。要注意 stammerer 這個名詞在英文裡已經偏舊、偏標籤化，現在多說 a person who stammers（有口吃的人）。另外英式說 stammer、美式多說 stutter，意思一樣。