平行
當對等連接詞 (and, or, but, yet, both…and…, not only…, but also…, neither…nor…, either…or…, not…but…) 出現時，前後所使用的結構要帄行對稱。一般而言，帄行的可歸納為下列幾種情況：
1. 詞類的帄行：這是最基本，最直接的帄行。
例：
1. Jane is young, enthusiastic and intelligent. (形容詞帄行)
2. He is good at playing both the piano and the guitar. (名詞帄行)
3. Not only did he buy me a watch but he also bought me a bike. (子句帄行，not only所引導的句子要倒裝)
4. I would rather swim than play basketball. (原形動詞帄行)
5. He neither drinks nor smokes. (動詞帄行)
2. 語意上的帄行：名詞與名詞帄行時，要特別注意到語意上是否合乎邏輯。下列句子雖然詞類上帄行，但語意上卻未帄行。
例：1. Nowadays students are more interested in business administration, international trade, and engineer. (應將engineer改為engineering)
2. Floriculture(園藝) is an art, business and scientist. (應將scientist改為science)
3. 單複數，時態上的帄行
例：
1. He neither knows nor cares what happened. (帄行現在式)
2. From the ship, they have found a lot of objects such as coins, bottles and jewelry. (帄行名詞帄複數，jewelry為不可數，故用單數)
