go to the theatre

The writer went to a theatre. He didn't* enjoy the play. A man and a woman were sitting behind him. They were talking loudly. The writer couldn't hear the actors. He turned around and said, 'This is a private conversation!'

I would use he couldn't enjoy the play, rather than he didn't enjoy the play. Couldn't would mean that there was a problem (the couple behind him talking) that stopped him from enjoying the play, while didn't means that he simply didn't like the play, that the play was bad.

As Tim said, 'This is a private conversation!' is something you would  say to someone listening or try to enter a private conversation, not to people speaking too loudly, disturbing you.

You should take care of punctuation. At the end of every sentence you should put a punctuation mark. It should be next to the last word in the sentence. Then you should leave a space and begin your next sentence with a capital letter. (He made lunch for his daughter. His wife was working all day.)

I also corrected your punctuation concerning direct speech, but that is not something you should worry about at this stage of learning English. However, I will give you a couple of examples, just to see what I am talking about:

Type 1
He said, 'Your English is getting better.'
She responded, 'Thank you.'

Type 2
'Your English is getting better,' he said.

'Thank you,' she responded.
 

Both ways are correct. 

 

I hope this helped :)
Zad 

go to the theatre

The writer went to a theatre. He didn't enjoy the play. A man and a woman were sitting
behind him. They were talking loudly. The writer couldn't hear the actors. He turn around and said"This is a private conversation!"

Put the punctuation right after the word, then leave a space.

The first word in a sentence starts with a capital letter.

"This is a private conversation!" is something you would say to a person trying to listen or join a conversation that is private. The writer probably said "Shut up!"