Oraciones condicionales:

-Primera condicional: if + present simple -> future simple o may/might imperative. ejemplos: if you are left-hande,you will face many disadvantages.You will meet a lot of people if you travel abroad.If she is free tomorrow,she may/might attend the concert too.-Segunda condicional:If + Past simple-> would + base form o could/might. Ejemplos:If we had enough money,we would buy a new car.You could/might learn more this year if you studied harder. - Tercera condicional: If+ past perfect -> would have +past pariciple o could/might have. Ejemplos: If I had phoned my parents,they wouldn't have been worried.He could/might have visited her if he had known she was ill.

-LA VOZ PASIVA:

Present simple:(activa)Nasa studies other planets ->(pasiva)Other planets are studied by Nasa.

Past simple:(activa)Nasa studied other planets->(pasiva)Other planets were studied by Nasa.

Future simple:Nasa will study other planets->Other planets will be studied by Nasa.

Modals:Nasa should stufy other planets->other planets should be studied..

Present continous:Nasa is studying..->Other planets are being studied by nasa

VOZ PASIVA

 Past continous:Nasa was studying ...->other planets were being studied by nasa.

Present Perfect simple: Nasa has studied..>Other planets have been studied by nasa.

Past Perfect simple:Nasa had studied other planets >Other planets had been studied by nasa.

Modals perfects:Nasa must have studied other planets>Other planets must have been studied by..

Have to:Nasa has to study other planets>Other planets have to be studied by Nasa.

be going to:Nasa is going to study other planets>other planets are going to be studied by..

-REPORTED SPEECH:

Present simple:She said that he worked as a policeman

Past simple:She said that hehas worked as a poli..

Future Simple:She said that he would work as a p..

Present continous:She said that he was working as

Pas continuous:She said that he had been working

Present perfect simple:She said tat he had worked

Present perfect continuous:She said that he been working as a policeman.

Past Perfect simple:She said that he had worked..

Past Perfect continous:She said that he had been working as a policeman.