The function of the Gerund:

Swimming is useful for health. (плавание полезно для здоровья

if we had met anna we would have told her everything.

b: then where have you been? (present perfect)

a: oh, nowhere. i wanted (past simple) to go to america two years ago,but now i don't want to go there.

b: why?

a: i understood (past simple) that my wish is impossible, so i abandoned(past simple) that idea. 

и 2-я

b: have you heard some interesting news? (present perfect)

a: no.

b: i heard (past simple) that brian flunked (past simple) his exam last week. 

a: why did (past simple)he flunk the exam?

b: he lost (past simple)his homework, so he didn't repeat a topic.(past simple)

если нужно использовать только формулу " i  " , то:

i can build a farmhouse.

i can go across the bridge.

i can dig in the garden.

i can ride a horse.

  5  предложениe

the university of california and the state university of new york are two examples of such public schools.