For torn shirts, replace the shoulder, for torn pants, change the pant leg.
This is advice on patching and sewing torn clothes. This is similar to “A stitch in time saves nine” (i.e., one should mend a small tear (or problem) with one stitch before it gets bigger requiring nine stitches (or more effort to fix)).
Ponds have shores, rivers have banks.
The meaning is describing how everything has boundaries and limits and rules should be respected. This is similar to “Toe the line” (i.e., following the rules) or “Draw the line” (i.e., setting a limit that must not be breached).
Who chooses the house door to crawl out.
The meaning is describing circumstances beyond one’s control (e.g., in which house/family to be born) that have to be accepted. This is equivalent to “Like it or lump/leave it,” “What will be will be,” or “In the lap of the gods.”
Weaver girl and cowherd.
The meaning is describing the separation of husband and wife by comparing them to the Cowherd (Ngưu Lang) and the Weaver Girl (Chức Nữ). The Cowherd, symbolizing the star Altair, and the Weaver Girl, symbolizing the star Vega, were banished to opposite sides of the heavenly river (i.e., the Milky Way). Every year, they are only allowed to reunite on the 7th day of the 7th month of the lunar calendar through a bridge formed by a murder of magpies (crows). This is similar to the star-crossed lovers Romeo and Juliet.
Who knows how to shape the hook to fit the fish’s mouth.
The meaning is (i) it is not possible to choose something pleasing to another person and (ii) one cannot know and plan for everything. This is similar to “Hit or miss” (i.e., something unpredictable) or “You cannot please everyone” (i.e., someone will always complain no matter what you do).
Each knows one’s role.
The meaning is (i) each person minds own business and does not interfere with others and (ii) each person has own destiny and does not compare with/should not be jealous of others. A variant is “Voi biết voi, ngựa biết ngựa / Elephants know elephants, horses know horses.” This similar to “To each his own”, “Mind your own beeswax” and “March to the beat of one’s own drum.”
Who knows if the raw rice is about the pot or the lid.
This is describing marital problems and not knowing who caused them. A married couple is often referred to as a pot and lid for cooking rice and raw/uncooked rice refers to marital problems. This is equivalent to “Relationship on the rocks” where bickering couples are compared to a ship in dangerous areas.
Who knows which crow is male and which is female.
This is describing something no one cares about or knows about. This is similar to “Not know beans about” or “Beats me.”
Each defends his own lord.
This is describing loyalty and how people side with their leader without regard to whether he is good or bad. It is a variant of “Chích khuyển phệ Nghiêu / Zhi’s dog barks at Emperor Yao.” Zhi is a fictional robber in Chinese literature known for evil while Emperor Yao of China is a legendary ruler known for his morality and intelligence. This is similar to “True blue” and “Unwavering loyalty.”
Someone says sticky rice he agrees to sticky rice, someone says meat he agrees to meat.
This is describing a person who only knows to follow and does not have his own opinions. This is a variant of “Quan tám cũng ừ, quan tư cũng gật / Eighth rank official seconds, fourth rank official nods,” describing how lower rank officials in the imperial court would second the opinions of the higher rank officials. This is equivalent to describing “yes man” or “sheep.”