Present Perfect vs Past Perfect:
1 builda) Look at this concert hall! They
it recently.b) They
most of the cathedrals before others came to their land.2 be marrieda) By the time their first baby was born, my friends
for 5 years already.b) I
(never).3 knowa) Last week I was introduced to George. I
him before.b) Michael is a cool guy. I
him for ages.4 worka) When my father was promoted to a senior position, he
at the factory for 20 years.b) I
with her since my first day in this company.5 leavea) Mary
(just) the office.b) By the time the bell rang, everyone
(already).6 Mary and John are such a lovely couple. I
always
them. (like)7 My aunt is in poor health. She
in hospital since Monday. (be)8 Parents
to their children before the party, so they behaved quite well. (talk)9 I didn't introduce Katie and Ann to each other, they
already
before. (meet)10 I am going to the library to return this book. I
it already. (read)