who

Hello,

I have to join these sentences using "who", where/that/whom /whose etc.

1. The girl was injured in the accident. She is now in the hospital.

a) The girl who was injured in the accident is now in the hospital.

b) The girl ,who was injured in the accident , is now in the hospital.

Which one is correct?

2. Summet has a dog. It is called Bruno.

a) Summet has a dog which is called Bruno.

b) Summet has a dog that  is called Bruno.

c)Summet has a dog who is called Bruno.

Whic one is correct among (a), (b), (c)?

3.) Ram is a widower. His wife has died. He has not re- married.

a) Ram is a widower whose wife  has died has not re-married.

b) Ram is a widower , whose wife  has died,  has not re-married.

Which is correct between (a) and (b)?

I also want to know in what situation comma is needed?

1.  I think 1a) is correct.  I would not use commas -- who was injured in the accident is important.  It defines the girl in this sentence.

2.  Regarding that or who for the dog Bruno, Webster's Dictionary of English Usage says:

In current usage, that refers to persons or things, ... , who chiefly to persons and sometimes to animals.

I prefer who for pets -- c).  I think Benita's suggestion also works, as does ...dog named Bruno.

3.  Both a) and b) need slight changes.

a) Ram is a widower whose wife has died; he has not remarried. [Remarried is not hyphenated.]

b) Ram, a widower whose wife has died, has not remarried.

In my a), whose is a relative adjective that introduces the subordinate clause whose wife has died, which modifies widower. Just as one would not pause when speaking, a comma is not used before whose.  Either a semicolon, as shown, or a comma and conjunction, such as and,  must precede the final clause -- he has not remarried.

I prefer my b) to either version of a).  A widower whose wife has died is an appositional phrase that "renames" Ram.  Just as one would pause before and after that phrase when speaking it, it is surrounded by commas.  Appositional phrases are usually enclosed by commas.