Phonetic, prosodic and linguistic analysis of intonation occurring in Nepali speech have been done in this paper. Different types of intonation patterns depending on various factors and types of sentences were identified and studied. In addition to pattern identification, a discussion has also been done on the significance of incorporating intonation while developing a Text-to-Speech system. Further, analysis has also been done on how intonation patterns are affected by different parts of speech. The investigation shows how nouns, verbs, adjectives, adverbs and other linguistic elements affect the rise and fall of the pitch. The dataset used for the analysis includes audio recordings obtained from All India Radio, Kurseong.