"rádi" is for plural masculine and it can be either:
my máme rádi - we like vy máte rádi - you (pl.) like oni mají rádi - they like
This construction "mít rád" is connected to gender of the person, rather than pronouns. So, it will also be:
on má rád - he likes ona má ráda - she likes
já mám rád - I like (for a man) já mám ráda - I like (for a woman)
Does ráda\rád depend on the the gender of the author of the sentence or on the gender of the thing that's being liked? And what's used for plural ?
Děkuji! I didn't notice that comment at first, it all makes sense now! :D
Koho is the accusative case in this sentence, as the object of the verb. Kdo is nominative.
The pronoun is declined and has different cases in the same way nouns do. Mít rád requires the accusative case for the object and hence the pronoun in the question is in the accusative case.
Remember, in English the pronoun can change too, although it may sound old-fashioned: who->whom.
Once "má ráda" means she likes sthg, other times the solution is that she likes sthg. MORE than anything else.
What is the exact meaning of this word?
mám rád/ráda - I like
mám raději - I like more (comparative)
mám nejradši - I like the most (superlative)
It is an adjective in the nominative form with the meaning of an adverb. Do not translate it on its own at your stage of learning.