Please clarify the usage of that and who. for example, in the following sentences, which of these would be correct –
a) The man that killed the tiger was arrested OR The man who killed the tiger was arrested.
b) He is the man who would be the king OR, he is the man that would be the king.
c) My car that/which/who I bought last year is broken.
Technically, we can use both ‘that’ and ‘who’ when talking of people though sometimes people prefer using ‘who’ as using ‘that’ seems to give an impression that the person you are talking about is somewhat less than human.
However, as per rules, you can use both that and who when talking of men/women:
1) He is the man who saved the girl. (Using ‘that’ in place of ‘who’ would be correct too though some may feel that using ‘that’ makes it less polite)
2) A man that lies cannot be trusted. (We can use ‘who’ as well)
When talking of animals, we generally prefer that:
1) The dog that bit me was mad.
2) The donkey that I bought from the village flies in the night.
However, sometimes people like using ‘who’ when talking of their pets because they think the animals are unique personalities and individuality.
1) My dog who my girlfriend gifted me is very nice.
2) Our buffalos who we bought last month have been lucky for us.