For number 3, you wrote the present perfect form of
llegar. You used the right verb, and the conjugation you used sounds right, but you need to make sure a compound form can be used. If not, use one of the
simple past tenses-
pretério imperfecto o pretério perfecto simple-instead. Look here for the conjugations of
llegar.
The page is divided into 'simple' and 'compound' forms.
You can enter the other infinitives, too, to see how they are conjugated.
Number 4 is another case where the
pretérito perfecto compuesto was used. It may need to be changed to the
simple form. You chose the correct verb.
Number 5 is correct.
Number 6 is also correct.
I believe the verbs you used in number 7 and number 8 are reversed. Check if you can use the compound form.
The answer you chose for number 9 sounds right, but is a compound form. Just make sure that can be used.
Number 11 is correct (your second correction).