The objective of this paper is to present comprehensive principles of language spread that are applicable in post-globalized scenarios, by expanding upon and consolidating our already-published works in which had we studied different aspects of diachronic and synchronic linguistics and language dynamics including language dynamics in India. Admittedly, these principles and theories cannot be comprehensive, inclusive or wide-ranging enough to account for all dimensions of language spread in all possible scenarios at this juncture. However, we recommend a repository-type and a nomothetic approach which will allow for principles drawn from new and varied case studies and fieldwork from different contexts around the world to be generalized and extended to other contexts, with suitable annotations and clarifications regarding their anticipated general or context-specific use. These approaches are particularly relevant in post-globalized scenarios which we expect to be the norm, barring exceptions, given that the factors working in favour of a global long term, political, economic and technological socio-cultural integration are expected to outweigh those working against it. Thus, non contact-based scenarios are expected to be over-arching in the twenty-first century, and are expected to take precedence over contact-based scenarios in many cases, even though the latter can both directly and indirectly impact the former. Therefore, this paper takes into account work already done in the field of sociolinguistics, applied sociolinguistics, linguistic anthropology and applied linguistics, and recasts them and reassesses them in such a way, that their relevance to post-globalized scenarios is brought out. It also merges them with our theories and approaches in the field of linguistics, and brings them in line with our philosophy of the 'Globalization of science'. Thus, the approach and emphasis of this paper is quite different from other vital publications in this field.