呢4、吧2、的2、啊1

吗 turns a plain statement into a yes/no question: 你吃吗 means 'Do you eat?' — answer yes or no. 呢 works completely differently — it asks 'what about...?' and flips the topic back at someone. So 我很好，你呢 means 'I'm fine, and you?' You can never say 你吗 there. 呢 also hunts for something missing: 我的钥匙呢？ = 'Where are my keys?' Real life: a friend says 我周末去爬山, you reply 我呢？ = 'What about me?' Bottom line: 吗 asks whether, 呢 asks about.

吧 turns a command into an invitation. 走吧 = 'let's go' — you're holding the door open, not ordering anyone around. 啊 pushes those same words into nagging: 走啊 = 'come on, go already.' It adds impatience, or treats the answer as painfully obvious. Compare 吃吧 = 'go ahead, eat' with 吃啊 = 'eat, why aren't you eating?' Same two characters, totally different mood. Safe default: use 吧 with friends, coworkers, and strangers. Save 啊 for people you're genuinely close to.

我的书 uses 的 for ownership. Sentence-final 的 has a totally different job: it stamps the sentence with 'for sure, that's how it is.' So 他会来的 = 'He'll come' — said with a shrug of certainty. Cut the 的 and 他会来 sounds like a flat guess, not a confident answer. You also hear it when explaining a reason: 我坐地铁来的 = 'I came by subway.' That 的 quietly adds 'here's the reason, by the way.' Rule of thumb: 的 at the end means certainty or explanation, never possession.

呀 is not a separate word — it's 啊 arriving right after a vowel sound. Say 好啊 quickly and it naturally comes out 好呀. Same with 是呀, 对呀, 来呀. After an n sound, 啊 slides into 哪 instead: 天哪, 看哪. After the -ng sound it stays plain 啊, like 行啊. And 啊 is the all-purpose emotion tag, so it can even stand alone as a pure sigh: “啊……” ── [《你喜欢看老电影吗？》](/read/do-you-like-old-movies#s17)