I am a newbie and I have a problem with this sentence, should I use past continuous or past simple?
When I realized that no one was paying any attention to me I decided to go home. But just as I was leaving the party a beautiful blond girl....(walk) through the door and....(smile) at me.
Some of my friends tell me the answer is: walked and smiled => Because it's an "action taking place in the middle of another action".
Some of the other said: was walking and smiling.
I'm so confused.
Both versions are acceptable, although the version with the -ing verb form needs a minor tweak:
When I realized that no one was paying any attention to me, I decided to go home. But just as I was leaving the party, a beautiful blond girl walked through the door and smiled at me.
When I realized that no one was paying any attention to me, I decided to go home. But just as I was leaving the party, a beautiful blond girl [was] walking through the door and smiling at me.
The idea that one action interrupts another is by no means a given. What would that mean? She was walking but then had to stop in order to smile? People can do many things at the same time—including walking and smiling.
Assuming that two actions aren't happening at the same time, one action doesn't have to interrupt another one; it's at least as common, if not more so, for one action to simply follow another one.
The question here is, does the woman walk through the door and then smile at you—or do you see her walking through the door as she is smiling at you?
Both versions are grammatical. It's what actually happened that determines which phrasing is the most accurate.
Also, it's a mistake to think that the verb form itself determines if two actions happen sequentially or in parallel:
When I realized that no one was paying any attention to me, I decided to go home. But just as I was leaving the party, a beautiful blond girl walked through the door [as she] smiled at me.
When I realized that no one was paying any attention to me, I decided to go home. But just as I was leaving the party, [I saw] a beautiful blond girl walking through the door [before stopping] and smiling at me.
Walked and smiled sounds much more natural to this US English speaker.
Present participles like leaving, walking, and smiling are usually used to describe an ongoing process or action. That works fine for leaving, because you were in the process of leaving when something else happened. If you want to describe that another event happened and was completed, the simple past works best. Since the girl presumably finished the actions of walking in and smiling, walked and smiled sound more natural.
It's not grammatically incorrect to say was walking and smiling, but it changes the emphasis of the sentence, because now it says while you were leaving, another ongoing process was happening. This is completely possible (for example, "While I was leaving, my friend Jake was telling jokes in the kitchen") but it doesn't work well with the Just as I was in your sentence, which suggests an instantaneous interruption, not an ongoing process.
Your friends are right (walked and smiled) -- they are actions interrupting another (often 'longer' background) action.
I'm editing this for clarification, since 'interrupting' seems to have been misunderstood in the above comment. She wasn't "walking and then had to stop in order to smile". It's not her actions that interrupt one another. The background action is the protagonist's process of leaving the party (perhaps getting coat, bag, saying goodbyes whatever). In the middle of this, this beautiful woman comes in; that's the meaning of one action interrupting another. It's a standard way in TEFL to explain how the past continuous works with the simple past. The standard sentence (of course you can tweak it and change the grammar so that you can fit in two participles, but I don't really feel that helps explain the grammar) is: As I was leaving the party, a beautiful girl walked through the door and smiled at me.
The other version is not officially wrong, but it is an unusual way to use the language and sounds dreamlike, almost poetical. It makes the girl's entrance sound longer, extended, not something that interrupted his actions. So if that's the context, then it's ok. The 'standard' sentence, on the other hand, makes it sound as if she really grabbed his attention, so that he might even change his mind about leaving the party.
