Tooth vs Teeth
Tooth and Teeth are two words that are often used as interchangeable words though it is wrong to do so. There is indeed some difference between them when it comes to their usage.
The word ‘tooth’ is the singular form whereas the word ‘teeth’ is the plural form. This is the main difference between the two words ‘tooth’ and ‘teeth’. The word ‘tooth’ is often used with the word ‘ache’ as ‘toothache’. It is grammatically correct to say ‘toothache’, but it is grammatically incorrect to say ‘teethache’. So is the word ‘toothpick’. The word ‘teethpick’ is grammatically incorrect.
In the same way the word ‘teeth’ is often used in the collective sense as in the sentence ‘brush your teeth well in the morning’. In this sentence you can see that the word ‘teeth’ is used as the plural form of the word ‘tooth’ and it is also used in the collective sense. The idea that every tooth has to be brushed in the morning is got by the utterance of the sentence mentioned above.
Similarly in words such as ‘tooth-whitening’, it is interesting to note that the singular form is used in hyphenated words. The expression or the word ‘teeth-whitening’ is wrong. ‘Tooth whitening cosmetic procedure’ is the correct usage whereas ‘teeth whitening cosmetic procedure’ is an incorrect usage.
In the same way in sentences such as ‘show your teeth’; the word ‘teeth’ is again used in a collective sense and not in the separate sense. The dentist that examines a patient examines the teeth of the patient instead of a particular tooth to begin with. These are the differences between the two words ‘tooth’ and ‘teeth’.