The purpose of this thesis is to study functions and meanings of the word / [leej] / in the current Thai language. The data were collected from daily-life conversations of Thai people in general. The result of this research indicates that, there are altogether 5 words, each having its own separate function or functions and meanings, as follows: The word /[ leej] / , as a transitive verb functions as part of the nucleus or as the nucleus of the verb phrase. Its meaning is “over than” or “longer than” The word /[ leej] /, as an adverb functions as part of the modifier or as the modifier of the verb phrase. It has 5 meanings: immediately, forever, indication of the emphasis of the meaning of the adverb which co – occurs, indication of the emphasis of the negative and indication of the emphasis of the sentence expressing reasons to support the speaker’s opinion in order to convince the listener. The word /[ leej] /, as a preposition functions as part of the downgraded locational phrase, which may function as a constituent of a noun phrase or a verb phrase, or as part of the locational phrase which functions as a sentence constituent i.e. as a Locational Adjunct. Its meaning is to indicate the location of the succeeding noun phrase. The word /[ leej] /, as a pre – numeral functions as part of the numeral phrase constituent which in turn functions as a constituent of a noun phrase. Its meaning is to exhibit that the number exceeds the number of the specified numeral. The word /[ leej] /, as a clause linker functions as a linker of the clause in the complex or compound sentence, and as a linker introducing a Linked Sentence. Its meaning is to indicate results. The study consists of seven chapters. Chapter one is an introduction. Chapters two to six deal with the five words / [leej] /, one chapter each. Chapter seven is the conclusion and some suggestions for further studies.
