作为 + Noun - Expressing "as (in the capacity of) / to look upon (sth as)..." with "zuòwéi + Noun"
每一个人在出生年都有一种动物作为生肖，12年是一个周期。

…呢? - Expressed to soften the tone of questions with "...ne?" (used to make questions more indirect and uncertain in tone)
为什么生肖是这12种动物呢？

Time or Verb Phrase + (以)前 - Expressing "before" a specific time or action with "Time or Verb Phrase + (yǐ)​qián"
很久以前的一天，玉皇大帝说：“我要选12种动物做人的生肖，一年一种动物。选一天报名，先到的12种动物就是十二生肖。”

就是 + Noun / Noun Phrase - Expressing "just / only…" with "jiùshì + Noun / Noun Phrase" (places greater emphasis to eliminate other options in order to focus in on something)
选一天报名，先到的12种动物就是十二生肖。

Subject + 让 + Sb / Sth + Verb / Verb Phrase - Expressing "to make or let sb / sth to do sth" with "Subject + ràng + sb / sth + Verb / Verb Phrase" (causative verb)
猫担心早上睡过头，就让老鼠在那天早上叫它起床，老鼠说“没问题”。
它要给牛唱歌，可又说自己声音小，为了让牛听清楚应该站在牛身上唱。

Subject + 叫 + Sb / Sth + Verb - Expressing "to ask or order sb / sth to do sth" with "Subject + jiào + sb / sth + Verb" (causative verb)
猫担心早上睡过头，就让老鼠在那天早上叫它起床，老鼠说“没问题”。

没想到... - Expressing "didn't expect…" with "méi​xiǎng​dào…"
没想到老鼠口是心非，那天早上并没有叫猫，而是自己去报名了。

并 + Negative - Expressing emphasis on the negative with "bìng + Negative"
没想到老鼠口是心非，那天早上并没有叫猫，而是自己去报名了。

不是 / 没有…，而是… - Expressing "not / did not…, but rather…" with "bùshì / méiyǒu...，érshì..."
没想到老鼠口是心非，那天早上并没有叫猫，而是自己去报名了。

给 + Noun + Verb - Expressing a more informal "for sb / sth..." with "gěi + Noun + Verb"
它要给牛唱歌，可又说自己声音小，为了让牛听清楚应该站在牛身上唱。

Statement， 可(是)… - Expressing "but / however…" with "Statement，kě(shì)…" (more informal and a bit stronger in tone 但是)
它要给牛唱歌，可又说自己声音小，为了让牛听清楚应该站在牛身上唱。

又 + Verb / Adj. - Expressing "(once) again / also / and yet…" with "yòu + Verb / Adj." (used for past events)
它要给牛唱歌，可又说自己声音小，为了让牛听清楚应该站在牛身上唱。

为了... - Expressing "in order to / for the purpose of…" with "wèi​le..."
它要给牛唱歌，可又说自己声音小，为了让牛听清楚应该站在牛身上唱。

往 + Direction / Place + Verb - Expressing that the action of the verb is "to / towards (a certain direction / place)" with "wǎng + Direction / Place + Verb"
牛同意了，就背着它往前跑。

Verb + 下来 - Expressed after verbs to indicate a downward movement towards the speaker / location with "Verb + xiàlái"
老鼠赶紧从牛身上跳下来，第一个去报名了。

而… - Expressing "and / as well as / and so…" with "ér..." (indicates contrast, causal relation or change of state)
老鼠赶紧从牛身上跳下来，第一个去报名了。而一直背着老鼠的牛，只得了第二名。

Time or Verb Phrase + (以)后 - Expressing "after" a specific time or action with "Time or Verb Phrase + (yǐ)hòu"
从那以后，十二生肖的动物就这样排名了。