及 / 以及【jí / yǐjí】

及 means "and" in writing. It joins nouns, and in a list it goes before the last item, with 、 between the others.

You'll meet it in notices, forms, news and instructions. In conversation the same list takes 和.

• × 我喜欢猫及狗 → 我喜欢猫和狗

以及

以及 is the longer form. It can join everything 及 joins, and it also handles longer phrases, often after a comma.

Only nouns, not whole sentences

及 links things, not events. Two clauses take 而且, 也 or plain juxtaposition.

• × 他来了及我走了 → 他来了，我走了
• × 她唱歌及跳舞 → 她唱歌、跳舞 / 她又唱歌又跳舞

The items joined by 及 should be of the same kind. Before the last item, 及 is often followed by 其他 or 其 ("its, their"), as in 学生及其家长, "students and their parents".