There are two ways of doing Indirect Statements in Greek. The first is to use the Accusative and Infinitive Construction, where the subject of the indirect statement is put in the accusative case and the verb in the infinitive mood. (The other is the Construction with oti  and the Indicative or Optatative.)

Click here for Infinitive Paradigm.

 
ton Pausanian efh logou katarcein.
"He said that Pausanias was beginning a speech." (176 a 4)
 

o iatroV enomize se nosein.
"The doctor thought that you were sick."
 

upelabe touV polemiouV di¢ oligou epiqhsesqai.
"He answered that the enemy would attack soon."

Note:

1. There is no word for "that"

2. You use the same tense that the speakers did when they made the direct statement.

In the second sentence, the doctor actually thought: "You ARE sick." He used the present tense; therefore you use the present infinitive.
In the third sentence, he answered: "The enemy WILL ATTACK." So you use the future infinitive.

3. "I say that...not" = ou fhmi

ouk efh touV nautaV Aqhnaze pleusai.
"He said that  the sailors did  not  sail to Athens."

1.
Speaker is the subject of the indirect statement:
use the nominative, not the accusative.

Contrast:

o iatroV enomize autoV  nosein.   OR   o iatroV enomize * nosein.
The doctor thought that he himself was sick. (autoV is in the nominative, or * left out).

with:

o iatroV enomize se  nosein.
The doctor thought that you were sick. (se is in the accusative)

2.

Speaker is the object of the indirect statement:
use Indirect Reflexive Pronoun:
e instead of autoV / auth
sfaV instead of autoi / autai

Click here for Paradigm of the Indirect Reflexive Pronoun.

Contrast:

 oi nautai enomizon ton Kuklwpa  sfaV  apoktenein.
The sailors thought that the Cyclops would kill  them  (the sailors themselves).

with:

 
 oi nautai enomizon ton Kuklwpa  autouV  apoktenein.
The sailors thought that the Cyclops would kill  them  (some other people).

h gunh enomize se ta crhmata  oi  dounai.
The woman thought that you had given the money to her  (to the woman herself).

with:

h gunh enomize se ta crhmata  auth_i  dounai.
The woman thought that you had given the money to her  (to another woman).