4.3.1　Lexical Density

W ords can be categorized into content words and function words.Lexical density is a term to describe the percentage of content words in the total number of words in any given text.Content words（or lexical words）contribute to themeaning of sentences.Nouns，ad jectives，lexical verbs，lexical adverbs and numerals are considered as content words because they convey information in the communication.

Function words（or grammatical words）are words that have little lexical meaning or have ambiguous meaning，but instead serve to express the grammatical relationships with other words within a sentence，or specify the attitude or mood of the speaker.Functional adverbs，determiners，prepositions，auxiliary verbs，modal verbs，conjunctions，pronouns，interjections are considered as functional words.They contribute much to the syntactic structure and make the language well-organized together.

It should be pointed out adverbs deriving from corresponding ad jectives（as carefully，naturally，slow ly）are taken as lexical adverbs.O thers like alm ost，just，about are reckoned as functional adverbs.(https://www.daowen.com)

Lexical density is defined as follow s（Stubbs 1986）：

LD＝（number of contentwords／number of totalwords）*100

According to the formula，the lexical density of TETT is lower than OETT（52.49＆53.50）.This gives evidence to Laviosa's hypothesis“translational com ponent has a lower lexical density”.Since content words carry information in sentences，OETT offers more information about tourist attractions.Correspondingly，more function words in TETT lead to the em phasis on the syntactic structure.