examples of vikari sabd
lets take the example of "Bachha" shabd
1)Bachhon ne khana khaya
2)Bachhe ne khana khaya
3)Bachha khana kha raha hai
see the underlined words, it changes according to the need of sentence.In this case it is due to vachan and karak. This kind of word is called Vikari shabd.
Eg .ladki/ladka, ghar, gaadi, bus, bakri, etc.
Hope u got the answer of the question.
Sorry I dont have hindi text.