Fill in the gaps with the correct answer can/ can`t, could/ couldn`t or was/ were able to

When I arrived, I ______ see a few people waiting for the train.
1. can
2. could
3. was able to
Sam ______ speak Italian fluently, can`t he?
1. can
2. could
3. was able to
________ tie your shoelaces when you were four years old?
1. can
2. could
3. was able to
It was a very tricky question, but Tom _______ answer it.
1. can
2. could
3. was able to
I _______ hear what they were saying because the music was too loud.
1. can`t
2. couldn`t
3. was able to
Although it was difficult, the children ______ build a tree house.
1. can
2. couldn`t
3. were able to
I _____ understand what he was saying because he was speaking Spanish.
1. can`t
2. couldn`t
3. can
Steven ____ walk when he was one year old.
1. can
2. could
3. can`t
The door was locked so I ________ go inside.
1. can
2. could
3. wasn`t able to
I _______ run faster than my brother now.
1. can
2. could
3. was able to