The main verb is also called the lexical verb or the principal verb. This term refers to the important verb in the sentence, the one that typically shows the action or state of being of the subject

THE LIST OF USED LITERATURE

1. 
   Allerton D.J. Essentials of Grammatical Theory. Routledge, 1979. 34-pp
   
2. 
   Bernard Comrie, 1976. Aspect. Cambridge University Press
   
3. 
   Croft William. Typology and Universals. Cambridge UNI Press, 2003.
   
4. 
   Gabriele, Alison (2008). "Transfer and Transition in the L2 Acquisition of Aspect". Studies in Second Language Acquisition: 6.
   
5. 
   Gabriele, Allison; McClure, William (2003). "Why swimming is just as difficult as dying for Japanese learners of English" (PDF). ZAS Papers in Linguistics. 29: 1.
   
6. 
   Hawkins John A. The Comparative Typology of English and German: Unifying the Contrasts. London/Sydney: Croom Helm, 1986.
   
7. 
   Henk J. Verkuyl, Henriette De Swart, Angeliek Van Hout, Perspectives on Aspect, Springer 2006, p. 118.
   
8. 
   Kiyota, Masaru. (2008). Situation aspect and viewpoint aspect: From Salish to Japanese (Doctoral dissertation). University of British Columbia.
   
9. 
   Li, Charles, and Sandra Thompson (1981). "Aspect". Mandarin Chinese: A Functional Reference Grammar. Los Angeles: University of California Press. pp. 184–237.
   
10. 
    MacDonald, Jonathan Eric. (2006). The Syntax of Inner Aspect (Doctoral dissertation) (p. 1). Stony Brook University.
    
11. 
    Pye, Clifton (2008). Stacey Stowers; Nathan Poell (eds.). "Mayan Morphosyntax". Kansas Working Papers in Linguistics. University of Kansas. 26.
    
12. 
    Pye, Clifton (2001). "The Acquisition of Finiteness in Kʼicheʼ Maya". BUCLD 25: Proceedings of the 25th annual Boston University Conference on Language Development, pp. 645–656. Somerville, MA: Cascadilla Press.
    
13. 
    Robert I. Binnick (1991). Time and the verb: a guide to tense and aspect. Oxford University Press US. pp. 135–6. ISBN 978-0-19-506206-9. Retrieved 12 August 2011.
    
14. 
    Stanley Fish. "Devoid of Content." The New York Times, May 31, 2005. Also How to Write a Sentence and How to Read One. HarperCollins, 2011
    
15. 
    VAN OLPHEN, HERMAN (1975). "Aspect, Tense, and Mood in the Hindi Verb". Indo-Iranian Journal. 16 (4): 284–301. doi:10.1163/000000075791615397. ISSN 0019-7246. JSTOR 24651488. S2CID 161530848.
    
16. 
    Zhang, Yaxu; Zhang, Jingting (2 July 2008). "Brain responses to agreement violations of Chinese grammatical aspect". NeuroReport. 19 (10): 1039–43. doi:10.1097/WNR.0b013e328302f14f. PMID 18580575. S2CID 35873020.