In defining relative clauses, the relative clause identifies the person (*who*/*that*), thing (*which*/*that*), place (*where*) or reason (*why*) we are referring to. ***that*** can be used instead of *who* or *which*.

> *This is a law wich/that doesn't exist in England.*

The relative pronoun can be left out if it is the object of the verb in the relative clause
No commas are used before or after the relative clause.

> The woman (*who*/*that*) I spoke to on the phone last week told me the museum would be open.