Questions on relative clauses

[bizt]

Hi,

I've got a class to teach on relative clauses and I have some questions:


- which pronoun do I use for animals:

The great white shark is a type of fish which has sharp teeth (this one seems better to me) OR The great white shark is a type of fish who has sharp teeth

Tom is a cat which eats sushi OR Tom is a cat who eats sushi (this one seems better to me)

Does a name make a difference? I know for humans it's "who/that" and for objects/things it's "which/that", but I'm a little confused with animals and animals being referred by name.


- I've read that "that" can replace "who" / "which", is this always the case:

Birds are a type of animal which can fly
Birds are a type of animal that can fly

The second one, to me, sounds more natural but maybe they are both OK. Is there ever a case where, in a sentence with relative clauses, "that" cannot replace "who/which"



Anyway couple of random questions but would appreciate if anyone can shed a little light. Thanks

Bizt

[5jj]

We use 'which', not 'who' for animals, though pet-lovers may use 'who' for their pets.

'That' cannot replace 'who' or 'which' in non-defining clauses.