Utilizamos when, while and as para hablar sobre situaciones o acciones que ocurren simulteanamente.
- Pueden ser utilizadas para introducir una acción más larga de lo habitual en la que va a seguir otra acción que ocurre al mismo tiempo.
Ejemplos:
As I was sleeping, the door bell rang.
While you were studying, your friend called you.
Nota: La frase principal que incluye “as” o “while” puede estar en orden inverso.
The doorbell rang as I was sleeping.
Your friend called you while you were studying.
Nota: Se prefiere el tiempo continuo para la acción o situación más larga (was eating / are walking), sin embargo nota que podemos usar “as” y “while” en pasado simple simple con un verbo de estado.
As I was at home, the postman came.
- Preferimos usar “while” para hablar de dos acciones simultáneas que van / iban juntas.
Ejemplos:
While I was a taking shower, my mother was cleaning the attic.
My mother was cleaning the attic while I was taking a shower.
Nota: También podemos utilizar los tiempos simples para el mismo significado.
While I took a shower, my mother cleaned the attic.
- Preferimos usar “as” para hablar de dos cosas que cambian juntas en el tiempo.
As you eat more, you will gain more weight.
As you study more, you will get better grades.
- Utilizamos “when” para hablar sobre las fases de la vida.
When you were a kid, you used to be so shy. (y no “while” o “as”)
- Utilizamos “as” para hablar de dos eventos o acciones consecutivos o acciones que ocurren de manera simultanea.
As he opened the drawer, he took out an old photo.
Just as my father came in, the phone rang.
- Utilizamos reducciones con “when” y “while”.
Don’t forget to take a map with you when going camping.
Tell me when ready.
While a student, I used to live with me family.
Fuente: Grammarbank