it melts
it is melting
it melted
it has been melted
I would quit smoking
I will quit smoking
I quit smoking
I smoke
I would have bought a car
I bought a car
I will buy a car
I would buy a car
I would have gone on holiday last week.
I have gone on holiday last week.
I will go on holiday last week.
I go on holiday last week.
I would speak English very well
I will speak English very well
I would have speak English very well
I were spoken English very well
have been
has been
am
have
had been
has been
have
has been
will have been
have been
shall had been
is
will be
have been
have
are
I will buy something
I buy something
I bought something
I had bought something