tooth和teeth的区别

"Tooth"和"Teeth"都是指牙齿，但用法不同。"Tooth"是单数形式，用于指单个牙齿；"Teeth"是复数形式，用于指多个牙齿。例如，"I have a toothache"（我牙疼）指的是单个牙齿的问题，而"My teeth are white"（我的牙齿很白）则是指整体牙齿的状态。

When it comes to the English language, the distinction between 'tooth' and 'teeth' is an important one to understand. These two words are related to the same concept but differ in number and usage. 'Tooth' is the singular form, while 'teeth' is the plural. This distinction affects not only the meaning but also the pronunciation of the words.

Number and Form: 'Tooth' refers to a single tooth, whereas 'teeth' indicates two or more. This singular-plural relationship is straightforward, with 'tooth' being the singular form and 'teeth' the plural.

Pronunciation: The pronunciation of 'tooth' is [tuːθ] in both British and American English, while 'teeth' is pronounced as [tiːθ] in both dialects. This subtle difference in pronunciation is key to using these words correctly in speech.

Usage in Compound Words: When 'tooth' is part of a compound word, the entire compound word takes the plural form when referring to more than one. For example, 'toothache' remains 'toothaches' when referring to multiple instances of tooth pain.

Examples:

• "She had very pretty straight teeth." - This sentence uses 'teeth' because it refers to more than one tooth.
• "The front cog has 44 teeth." - Here, 'teeth' is used to describe multiple teeth on a gear.

Phrases and Idioms:

• "Tooth profile" - Refers to the shape of a tooth or gear tooth.
• "Tooth surface" - Describes the surface area of a tooth or gear tooth.
• "Long in the tooth" - An idiomatic expression meaning old or aged.
• "Tooth decay" - A common dental issue referring to cavities or caries.
• "Tooth root" - The part of a tooth that is anchored in the jawbone.

Word Definitions:

Teeth: The plural form of 'tooth', pronounced [tiːθ], referring to multiple teeth.

Tooth: The singular form, pronounced [tuːθ], referring to a single tooth or a tooth-like part.

Example Sentences:

• "Draw the floss backwards and forwards between the teeth." - This instruction uses 'teeth' to describe the action of cleaning between multiple teeth.
• "Many infants do not cut their first tooth until they are a year old." - Here, 'tooth' is used because it refers to the first single tooth that emerges.
• "When did she cut her first tooth?" - Again, 'tooth' is appropriate as it询问的是第一颗牙齿的出现。