English grammar: main clause

[Fisnik]

Hi, my name is Fisnik. I am studying English language and literature and one of my subjects is English Grammar. Presently, in English Grammar we are learning about "Clauses" and I was wondering if you could tell me in the following complex sentence which clause is the Main Clause.

"When I arrived at the airport, they told me that my plane had already left."

I read somewhere that the main clause is independent and it can stand by itself but this sentence has confused me.

Thank you in advance

[Yankee]

Hi Fisnik

The main clause is "they told me that my plane had already left."

Although "I arrived at the airport" would be a complete sentence, "When I arrived at the airport" is not a complete sentence.
.

[Michauek]

can we say "They told me that my plane had already left when I arrived at the airport" or does it change its meaning ?
_________________
Experience is the name everyone gives to their mistakes. Oscar Wilde
Michal. I'm an english student

[Yankee]

Hi Michauek

Yes, you can put the 'when' clause at the end without changing the meaning.