She made tea when the guests arrived.

[Alice Chu]

In the sentences below, the two actions (events) happened at the same time in the past. Is my understanding correct?

1. She made tea when the guests arrived.
2. He grabbed my arm when he fell.

 

[emsr2d2]

Well, yes and no.

In sentence 2, we can assume there was only a very brief gap between his realising he was falling and his grabbing the arm.

In sentence 1, there's probably more of a gap. I would take "when" to mean "shortly after" or "as soon as". You can't be making tea and letting your guests in through the front door at exactly the same time. Use logic. The doorbell rings. You open the door and welcome the guests inside. Once they've taken off their coats and sat down, then you probably go to the kitchen and make some tea.

 

[Tarheel]

My esteemed colleague is very patient. I would have simply said that in both cases one thing happened right after the other. (It might have been less than a second afterwards, but it was still afterwards.)

 

[Alice Chu]

What about the following sentences?
The two actions (events) happened at the same time in the past.

1. The music started when the curtains opened.
2. When he fell off the tree, he felt scared,

 

[Tarheel]

For the first one, I would say:

When the music started playing, the curtain opened.

For the second one, falling out of a tree and feeling scared are not both actions in the same sense. Perhaps:

When he hit the ground he hurt himself. (Ouch!)

 

[jutfrank]

1. The music started when the curtains opened.

If I understand you correctly, you mean this:

The music started as the curtains opened.

The idea is that both actions happened at the same time.

2. When he fell off the tree, he felt scared.

That's a very poor example sentence, for several reasons. Just forget it.

Please don't make up sentences and then ask us what you mean.

 

[Tarheel]

Alice Chu, jutfrank's sentence is better than mine. (I don't totally disagree with myself, but I think his sentence is better.) In sum, I agree with everything he said.

 

[Skrej]

2. When he fell off the tree, he felt scared,

To begin with, we don't fall off trees. We fall out of them.

Edit: Unless you're talking about a fallen tree lying on its side, then I suppose you could fall off it.