The Conjunction of time 'while'

1. Marion watched TV when/as/while I did the ironing.
   I did the ironing as/when/while Marion watched TV.
2. I left as soon as I saw Carla
   She waited until the phone rang
   She has been ecstatic since the phone rang.
3. I left as soon as/when I saw Carla.
4. Marion watched TV when/as/while I did the ironing.
   I did the ironing as/when/while Marion watched TV.
   She waited until the phone rang.
5. He left as I arrived.
   He left when I arrived
6. She waited until the phone rang.
7. She has been ecstatic since the phone rang.

Conjunction while
As a conjunction, while corresponds in meaning to the preposition during:
While you're at the swimming pool, I think I'm going to pop into town.
I made three phone calls while they were at lunch.
Some members of the audience fell asleep while he was talking to them.
(Some members of the audience fell asleep during his talk.)

Within a sentence, while is used to refer to a simultaneous time relationship between two actions or states:
Geoff phoned while you were walking the dog.
While I watched the match, Jill watched a film on the other TV.
Was the package delivered while I was working out at the gym?

While can be used in clauses where the subject and the verb to be are ellipted:
While holidaying in Malaysia, they received the news that their daughter had secretly married.
(While they were holidaying in Malaysia )
While on the subject, why don't we write a joint letter of complaint to the hotel?
(While we are on the subject )
Do not depress the button while dialling.
( while you are dialling )
While can also be used to contrast two ideas or statements; a clause with while is put first and is then followed by a contrast. In this meaning, no time relationship is expressed:
While it is clearly a good idea to involve them, I don't think they should be included in everything.
While the university regrets the incident, it cannot be held responsible for cars parked in its car parks.

Whilst
Whilst is a more formal alternative to while and is normally only found in writing:
Whilst the company accepts the apology, it is still to decide whether to take matters further.

As and while are sometimes confused. As not while is used to describe two situations which change in parallel:
As they get more experience, their tactics will become more sophisticated.
(While they get more experience, their tactics will become more sophisticated.)