It's impossible to provide an exact number of words in English, since new words are being added to the dictionary, and falling out of use constantly. 【小题1】

The short answer is: about a million. Doubt you know anything even close to a million words? That number includes any number of legal, medical, scientific, and mechanical terms that most people will never meet in their day-to-day lives. 【小题2】

The “million" number also includes the many, many words that have fallen out of use throughout the time.【小题3】 Consider the word “diddle"，a slang term from the 1700s that means “gin". Many English speakers would recognize “gin"，but far fewer would recognize “ diddle”.

If a million words is the absolute upper level, how does that compare with the general vocabulary of most English speakers? 【小题4】 Most English-speaking adults know between 20,000 and 30,000 words. And in addition to those many thousands of words, they're probably able to comprehend a good 20,000 more just from context clues.

【小题5】 You won't find a single dictionary that includes anywhere close to the total million words. One of the reasons is that general-usage dictionaries don't include lots of technical terms—both because of how uncommon they are and, in some cases, because of length. The longest word in the English language is a term from chemistry that is used to identify a certain kind of protein. It is 180,000 letters long. So you certainly won't see it in the dictionary.

Many countries around the globe pride themselves on their lingual diversity. Here are a few of the most polyglot places on Earth.

Aruba

Aruba sits in the far southern Caribbean sea near Venezuela. Dutch is an official language and is taught in all schools, both English and Spanish are also compulsory(必修的)languages in Aruba’s education system. However, none of these languages is considered the native language of Aruba on the street, at home locals communicate with one another in Papiament. Papiamento is an official language alongside Dutch, and it is used regularly in the media and in government.

East Timor

This tiny young nation sits in the far south-eastern comer of the Indonesian Archipelago. Once a colony(殖民地)of Portugal, Timor decided to adopt Portuguese as an official language after independence. The local tongue, Tetum, is the most widely spoken language on the street. In addition, English and Indonesian are used throughout the country, and both are officially recognized as working languages.

India

Hindi and English are the official national languages of India, and the majority of educated Indians have knowledge of both, though English is preferred over Hindi in southern India. Each state in India has its own official language (s), most of which differ from Hindi. These languages are used in the local media and on the street.

South Africa

South Africa has 11 official languages. In many urban areas, English is the lingua franca (通用语). It is also the main language of the government and media, even though less than ten percent of South Africans speak it as a first language. Afrikaans, a Germanic language similar to Dutch, is spoken in the southern and western regions of the country. South Africa has nine official Bantu languages, of which：Zulu and Xhosa are the most common.

Language is always changing. In a society where life continues year after year with few changes, the language does not change, either. The earliest known languages had difficult grammar but a small, limited vocabulary. Over the century, the grammar changed, and the vocabulary grew. For example, the English and Spanish people who came to America during the sixteenth century gave names to all new plants and animals they found. In this way, hundreds of new words were introduced into English and Spanish vocabularies. Today life is changing very fast, and language is changing fast too.

There are several major language families in the world. Some scientists say there are nine main families, but other scientists divide them differently. The languages in each family are connected, and scientists think that they came from the same parent language. About 3 percent of the people in the world speak languages that are not in these major families.