The purpose of this thesis is to study the structure of the Nucleus which is a constituent of verb phrases. The data was drawn mostly from the language spoken by the writer herself. Some material was taken from everyday conversation of other people in Bangkok. It has been found that the Nucleus of a verb phrase must consist of a verb and may consist of a pre-verb, a post-verb or a verbal linker. Thirty patterns of the structure of a Nucleus which is composed of verbs only have been found. Words in the other three classes may also be found in all these patterns but their positions vary: pre-verbs occur in the first position, post-verb may occur in the final position or between verbs, and verbal linkers always occur between verbs.