Theorie:

Reported Speech
 
Reported speech is used to tell somebody what another person says or said. There are various different reporting verbs, e.g. say, tell, mention, point out, argue, complain, whisper, shout, announce, ...
 
In case the reporting verb is in PRESENT TENSE, only the person of the reported speech changes. However, if the sentence starts with a reporting verb in PAST TENSE the person as well as the tense of the reported speech need to be changed. Have a look at the following examples:
 
 
Beispiel:
PRESENT TENSE:
 
Direct Speech: Mary tells me, "I am working in a restaurant."
 
Reported Speech: Mary tells me that she is working in a restaurant.
 
Explanation: The PERSON has changed: I has turned into she. (Don't forget to add the third person "s" !)
 
 
PAST TENSE:
 
Direct Speech: Mary told me, "I am working in a restaurant."
 
Reported Speech: Mary told me that she was working in a restaurant.

Explanation: Not only the PERSON has changed: I has turned into she, but also the TENSE: Present Progressive (am/is/are working) has turned into Past Progressive (was/were working).
 
The tenses are changed as follows:
 
Direct Speech
Reported Speech
Present Tense
Past Tense
Present Progressive
Past Progressive
Past Tense
Past Perfect
Past Progressive
Past Perfect Progressive
Present Perfect
Past Perfect
Past Perfect
Past Perfect
Present Perfect Progressive
Past Perfect Progressive
Future
Conditional I
Conditional I
Conditional II
 
 
Similarly, the time expressions need to be changed:
 
Direct Speech
Reported Speech
now
at that time / then
today
that day
yesterday
the day before
last night / week / month
the night / week / month before
tomorrow
the next day / the following day
 
 
 
REPORTED QUESTIONS:
 
Usually reported questions are introduced with the verb "ask" followed by
 
if / whether              in yes/no questions or
 
a question word    in extended questions.
(e.g. what, when, where, why, who, how)
 
 
Apart from that, reported questions also require a change of pronouns, tenses (backshift) and time expressions (e.g. yesterday), similar to the reported speech / statements.