Q:

Generally expanding knowledge.

If a person tells more than four people about zina that the person has engaged in,out of fear,for example.

And if for example if a person had told four people about a zina,forgot if the person actually told four people.

1)Question is,does telling four people mean that for sure ,the person has to get the hadd punishment?

Or can the person still ask for forgiveness from Allah?

2)And in the other scenario,if the person forgot whether they told four people,does that person still need to get hadd punishment.

3) if out of the four witnesses,one says to conceal it,does it mean the person doesnt have that person as a witness

A:

The proof to incur the penalty of adultery is only established through the testimony of four people who confirm that they have personally seen both parties engaged in a sexual intercourse.

It is also established through confession or by pregnancy.

Someone’s telling four persons that he committed adultery cannot prove the crime. 

The following verse makes it clear that four witnesses are necessary to prove the crime, “And those who accuse chaste women and then do not produce four witnesses – lash them with eighty lashes and do not accept from them testimony ever after. And those are the defiantly disobedient.”  (An-Nur 24: 4)

In the case of your question, it is highly encouraged that a person does not reveal it to people and repents his sins. This is based on the report of Maidh who committed adultery and came to admit his crime before the Prophet.

According to the Imam Malik’s Muwatta’, Said ibn al-Musayyab reported that a man from the Aslam tribe came to Abu Bakr As-Siddiq and said to him, “I have committed adultery.” Abu Bakr said to him, “Have you mentioned this to anyone else?” He said, “No.” Abu Bakr said to him, “Then cover it up with the veil of Allah. Allah accepts repentance from his slaves.” His self was still unsettled, so he went to Umar ibn Al-Khattab. He told him the same as he had said to Abu Bakr, and Umar told him the same as Abu Bakr had said to him. His self was still not settled so he went to the Messenger of Allah, may Allah bless him and grant him peace, and said to him, “I have committed adultery,” insistently. The Messenger of Allah turned away from him three times. Each time the Messenger of Allah turned away from him until it became too much. The Messenger of Allah questioned his family, “Does he have an illness which affects his mind, or is he mad?” They said, “Messenger of Allah, by Allah, he is well.” The Messenger of Allah said, “Unmarried or married?” They said, “Married, Messenger of Allah.” The Messenger of Allah gave the order and he was stoned.  

Allah Almighty knows best.