Would rather is used to express preference and is interchangeable with would prefer. It is used in short conversations to state or ask about preferences between choices. While rather is not a verb, it is part of the expression would rather which is followed by the base form of a verb. Would rather can refer to present or future preferences and is often used with than to compare two specific choices.

2.  Would rather is used to express a
preference in English. Would rather is the
same in meaning as would prefer. These
two phrases are used interchangeably to
express a preference when making a
choice.
 Here are some examples of short
conversations that use would rather to
either state or ask for a preference.

3. John: Let's go out tonight.
Mary: That's a good idea.
John: How about going to a film? There's a new
film out with Tom Hanks.
Mary: I'd rather go out for dinner. I'm hungry!
Sue: I'm not sure which topic to choose for my
essay.
Debby: Well, what are your choices?
Sue: I can write about the economy or about a
book.
Debby: Which would you rather write about?

4.  The form would rather is a little strange
because 'rather' is not a verb but is part of
an expression that means 'would prefer to'.
'Rather' is usually immediately followed by a
verb in base form (verb without 'to'). It's
common to use would rather in the
shortened 'd rather form in positive
statements. All subjects take 'would rather'.
Would rather can be used to refer to the
present moment or a future moment in
time.

5.  Subject + would rather ('d rather) + base
form of verb
 Peter'd rather spend time on the beach.
I would rather learn a new language
than study math.

6.  Would + subject + rather + base form of
verb + complement
 Would you rather stay at home?
 Would they rather do homework
tomorrow morning?

7.  Would rather is often used with 'than'
with two verbs or objects when making a
choice between two specific actions.
 Would you rather work for Tom than for
Mary?
She would rather play tennis than go
horseback riding.