to be to is the synonymous to have to and is realized depending on the form and lexical meaning of the infinitive following it. Mostly -мати, even повинен, мусити. According to the agreement rent was to be paid in advance. - Згідно угоди, кварт платня повинна була сплачуватися наперед.
When expressing inevitability of some action or event - мати. If the thing was to happen it was to happen in this way. - Якщо вже це мало скоїтись, то воно мало скоїтись саме так, а не інакше.
То be (to) may express треба. It was to be expected happen in this way. - Цього і треба було чекати.
When expressing possibility, to be (to) is translated as можна, мати, можливо: There is a good training to be had there. - Там можна пройти гарну практику / вишкіл.
То be (to) may be translated by the strictly logical position of the parts of the sentence or peculiar logical sentence structure.
1.6. Ought tolike the modal verb should expresses:
a) moral obligation, presupposition, desirability, advisability. They are close to треба or слід, потрібно. Oh, I've forgotten, I ought to have asked her about that - О, а я й забув: я ж мав (повинен був) запитати її про те.
in the context of the assumptive duty or obligation, necessity ought to is expressed through the particles б, би, щоб: You ought to be working now- Ти ж мав би бути на роботі зараз.
the conditional subjunctive meaning through якби, якщо. You ought to have seen her - Бачили б ви... Треба було бачити...
ought to expressing desire or affirmation - певне, напевне, мабуть. She ought to have been thinking about spending her money. - Вона, мабуть, подумує вже про те, як потратити свої гроші.