There are plenty of set phrases in Chinese. Set phrases are idiomatic expressions usually made up of four characters, and contain within one sentence, a single and complete meaning. Having a close study on the formation of set phrases helps substantially the learning.
The first two characters and the last two are parallel/two pairs are parallel
1. Two pairs of subject-predicate structures
龙飞 dragons fly, 凤舞 phoenixes dance, 龙飞凤舞 lively and vigorous in calligraphy; 心灰 the heart is grey, 意懒 the mind is lazy, 心灰意懒 disheartened; 面红 the face is red, 耳赤 the ear is red, 面红耳赤 be flushed
2. Two pairs of predicate-object structures
藏头 hide the head, 露尾 expose the tail, 藏头露尾 tell part of the truth but not all of it; 营私 seek private gain, 舞弊 conduct illegal transactions, 徇私舞弊 engage in malpractices for selfish ends
3. Two pairs of modifier-noun structures
腥风 a foul wind, a rain of blood 血雨, 腥风血雨 sanguinary slaughter; 镜花 flowers in a mirror, 水月the moon in water, 镜花水月 an illusion
4. Two pairs of parallel structures
喜怒哀乐 happy or angry, sad or joyous; 是非曲直 right and wrong, proper and improper
Two pairs are not parallel
1. The first pair is subject and the second one is predicate.
面目可憎 appearance is repulsive [disgusting; ugly]; 蚍蜉撼树 an ant is trying to shake a giant tree
2. The first pair is predicate and the second pair is object.
好为人师 like to be a master to others; 如坐针毡 as if sitting on a spiked rug/be in an extremely uncomfortable position; 顿开茅塞 become enlightened at once
3. The first pair modifies the second pair.
世外桃源 land of idyllic beauty；近水楼台 a favourable position; 扶摇直上 rise directly to a high position
4. Object of the first pair is the subject of the second.
引狼入室 invite [bring] a wolf into the house; 化险为夷 change danger into safety; 认贼作父 treat a thief as one’s father 请君入瓮
5. Both the first and second pair are predicate-object structure, but the two pair don’t have any relation of modifying-being modified.
画蛇添足 paint a snake with feet; 守株待兔 stand by a tree stump waiting for a hare to dash itself against it
After learning the formation of set phrases, do you feel a bit relaxed to move on?