This is the 454th most frequent Swedish word.
försökte
"Försökte" means "tried" in English.
In this sentence, 'försökte' is used to indicate an attempt made by the subject, 'Hon', in the past tense.
Hon försökte öppna dörren, men den var låst.
She tried to open the door, but it was locked.
'Försökte' here conveys an action of attempting or striving to do something, undertaken by 'De' (‘they’) in the past.
De försökte att förstå instruktionerna, men det var svårt.
They tried to understand the instructions, but it was difficult.
This use of 'försökte' expresses the speaker's effort in the past to accomplish an action.