Each of the above cases has a particular meaning attached to it. The concept of ‘कारक’ helps us to understand it!
1. I mango. There is a sense of incompleteness2. I eat a mango. The sentence is complete; we get to know the meaning of this sentence.
1. रामः फलं (Ram fruit) - the sentence is incomplete2. रामः फलं खादति (Ram eats fruit) – The sentence is complete and the complete meaning is understood
क्रियापद – Verb -> पद (word), क्रिया (action) -> a word that tells an action