If somebody talked about a situation that has still not changed
- that is to say, if the original speaker's present and future are
still present and future - a reporter can often choose whether
to keep the original speaker's tenses or to change them, after
a past reporting verb. Both structures are common.
- DIRECT: The earth goes round the sun.
INDIRECT: He proved that the earth goes/went round the
sun.
- DIRECT: How old are you?
INDIRECT: Are you deaf? I asked how old you are/were.
- DIRECT: It will be windy tomorrow.
INDIRECT: The forecast said it will/would be windy
tomorrow.
We are more likely to change the original speaker's tenses if
we do not agree with what he/she said, if we are not certain
of its truth, or if we wish to make it clear that the information
comes from the original speaker, not from ourselves.
The Greeks thought that the sun went round the earth.
(NOT ... that the sun goes round the earth.)
She just said she was fourteen! I don't believe her for a
moment.
He announced that profits were higher than forecast.
M.Swan PEU