Teeth is the plural. Tooth is the singular. Teeth's is the possessive plural and Tooth's the singular possessive. This is one way to form the genitive, the other being through of ("my tooth's enamel", "the enamel of my tooth").

This is all due to the fact that tooth is a countable noun, i.e. there is a singular and a plural form of the noun. The Capital Community College Foundation has published a very informative webpage about Count and non-Count Nouns , which you should read if you have difficulty telling the difference between countable and non-countable nouns.

The etymology of eye teeth is obvious - due to their position below the eye. The etymology of the whole phrase give one's eye teeth - I would attribute this to the importance of the canines. Carnivores, on the other hand, need canines to kill prey and to tear meat. Humans have four types of teeth - incisors, canine, premolar and molars.

2015年7月20日 · have teeth if a law or organization has teeth, it has the power to make people obey it [Example:] The committee can make recommendations but it has no real teeth. In U.S. legal settings, a law or regulation that is promulgated without including a meaningful enforcement mechanism is commonly referred to as being toothless .

by the skin of one's teeth and it's no skin off my nose, as this and this. The -teeth phrase seems to have originated in the southern US. This is a mixed metaphor, and yet another variation of "no skin off my nose/back/backside". The earliest "no skin off my teeth" I found in Google Books is from a 1938 The Atlantic monthly: Volume 162:

2015年4月2日 · From an idiomatic perspective, the expression was coined during the Middle Ages with the simple combination of two common terms. The second term, tooth, was already used idiomatically meaning 'taste, liking'. Sweet tooth (n.) : "fondness for sugary stuff," late 14c., from sweet (adj.) + tooth in the sense of "taste, liking" (see toothsome).

2017年7月5日 · @poeticGeek clicking your teeth would be something different. Perhaps try googling for examples of 'clicked his tongue' and see what you think of how others use it. There is more than one way to make a click with your tongue so you may have to say 'clicked his tongue in approval' or something to distinguish from tsking and tutting.

2018年2月16日 · It involves separating both the lips also besides tongue and teeth. But quickly. The combination of the quick separation - 1. of both lips 2. teeth and tongue from upper region of mouth (palate I guess) - make one sound that depicts frustration or disapproval. I personally find it offensive when someone makes it even for genuine reasons.

tooth → teeth goose → geese louse → lice mouse → mice. I-mutation is caused by the very human habit of laziness: taking the shortest distance between two points. The plural of man in ancient West Germanic, the ancestor of Old English, used to be a word something like *manniz.

2013年12月1日 · A horses teeth are regarded as a good guide to its age. When you buy a horse you check its teeth to see if they match the age of the horse according to the seller. If someone gives you a horse as a gift, it is considered ungrateful to check its teeth. You are pointedly drawing attention to your doubts about the quality of the gift.