ko is a very versatile particle in Hindi
Today’s usage is a bit similar to a and the in English
Radha akhbar paDh-ti hai = Radha reads the newspaper
Radha akhbar ko paDh-ti hai = Radha reads a certain newspaper
Radha sees a car =
Radha sees a certain car =
Because every human is unique, we will always use ko
Radha sees Amit = Radha Amit dekh-ti hai (wrong)
Radha sees Amit = Radha Amit ko dekh-ti hai (correct)
Rohit calls Sita = Rohit Sita ko bula-ta hai
Priya gives Suresh =
I tell Radha =
se = from
But for these 3 communicative words we will use se instead of ko:
bol, kah, pooch
Radha Sita ko pooch-ti hai (acceptable)
Radha Sita se pooch-ti hai (correct)
Radha speaks with Anita (kah) =
Radha talks with Anita (bol) =
mil = meet (most important meaning)
Here also we use se
Amit Sita ko mil-ta hai (acceptable)
Amit Sita se mil-ta hai (correct)
I meet with Anita =
Radha meets with Anita =
Radha meets with Anita’s mom =