Make tenses reflect meaning-MGMAT SC

[dddanny2006]

Past Progressive-A lot has been spoken about Present Progressive,but nothing much has been spoken about Past Progressive.

Past Progressive: Sandy was playing Soccer yesterday.

What is this supposed to mean.

In case of Past Progressive:Sandy is playing soccer.The present progressive indicates action happening right now,but whats not clear is what does the Past Progessive indicate?Yes I understand,that it happened in the past,but what does the to be verb+ '-ing' do to it additionally?Does it give it a time frame or something similar?Please clarify.

She was playing with her friends when the baby sitter arrived.

Whats the sequence of action in this?Did she just start playing,or was she already playing and continued on,or was it that she was already playing but stopped when the baby sitter arrived?What does the Past Progressive do here?

Now lets look at this one,both actions are in simple past here
She played with her friends when the baby sitter arrived.

According to Manhattan, in the above sentence the action played takes place after the babysitter arrived.How can we know this for sure?

Please explain the 'Past progressive' and 'when' concept.

Also please explain the difference between simple past and past progressive.I want to understand how they're different including the extended time frame the latter conveys.
Thanks

[ceilidh.erickson]

The difference between past progressive and simple past tense is that past progressive is an ONGOING action in the past, whereas simple past tense is a COMPLETED action in the past.

In the example She was playing with her friends when the baby sitter arrived.
At the moment when the babysitter arrived, the playing was an ongoing action. It was still happening when the completed action "arrived" took place. The "when" tells us that the completed action interrupted the ongoing action.

Whenever a "when" is used with two verbs in the same tense, though, it tells us something about the sequence of events. If I say:
When I arrive, you are always happy to see me
This implies that "I arrive" first, and "you are happy" happens afterward.

In your example:
She played with her friends when the baby sitter arrived.
Again, this implies that the babysitter arrived first, and she played afterward.

As to your question "how can we know this," well... it's just a particularity of English usage! "When" used with progressive tenses implies interrupted action. "When" used with the same tenses implies a sequence of actions.

[dddanny2006]

Thanks Ceilidh,
When you say ongoing action,does the action stop when the babysitter arrived?Or does it continue even after the babysitter arrived?Can you explain as to when the ongoing action started/ended?

In the example She was playing with her friends when the baby sitter arrived.
At the moment when the babysitter arrived, the playing was an ongoing action. It was still happening when the completed action "arrived" took place. The "when" tells us that the completed action interrupted the ongoing action.

[ceilidh.erickson]

When you say ongoing action,does the action stop when the babysitter arrived?Or does it continue even after the babysitter arrived?Can you explain as to when the ongoing action started/ended?

Actually, it's impossible to tell just from verb tense - both interpretations could be accurate. The rest of the sentence would have to give us more information:
She was playing with her friends when the baby sitter arrived, and she continued to play.
She was playing with her friends when the baby sitter arrived, but then she stopped.

[dddanny2006]

Ok.Correct me if Im wrong.
Past progressive is an ongoing action that happened in the past,it started some time in the past.When we say ongoing,till when is it ongoing?Is it ongoing till a certain point in time?

When you say ongoing action,does the action stop when the babysitter arrived?Or does it continue even after the babysitter arrived?Can you explain as to when the ongoing action started/ended?

Actually, it's impossible to tell just from verb tense - both interpretations could be accurate. The rest of the sentence would have to give us more information:
She was playing with her friends when the baby sitter arrived, and she continued to play.
She was playing with her friends when the baby sitter arrived, but then she stopped.

[ceilidh.erickson]

Past progressive is an ongoing action that happened in the past,it started some time in the past.

Absolutely correct. It started in the past, and was still ongoing at some other reference point in the past.

till when is it ongoing?Is it ongoing till a certain point in time?

We don't necessarily know. The verb tense alone doesn't tell us. The rest of the sentence would have to fill in that meaning for us.