Вставитьположительные или отрицательные формы глагола can , to be able в правильном времени. in very early times all the people on the the same language.they lived together and understand each other.if we all get together a great city/if it everybody will be happy. really fast.nowadays people many languages but most of english.
1. can
2. could
3. were able
4. can
5. are able
6. can
(не уверенна)
1.can
2.could
3.will be able
4.can
5.can(сомневаюсь,не вижу перехода времени)
6.can
7.can