Which sentence isn't grammatically correct?

Which preposition is missing in this sentence?

When I was a child, I was interested ... science and technology.

Match the English expressions to their Polish equivalents.

Which verb should be inserted into this sentence?

We asked him for help but he ...

The negative form didn't is the same for all persons in verb conjugation.

Complete the sentence using the past simple tense.

... Sam (enjoy) ... his trip to Wales last weekend?

Which of these verbs means mieć nadzieję in Polish?

When do we use these grammatical structures?