То be (to)

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 to like 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.

Need

Need is known to have 2 forms of realization, that of a defective verb and a regular verb with modal meaning. The double nature of need does not influence in any way its translation of треба, потрібно, необхідно. That needs a bit of thinking - Над цим треба ще трохи подумати.

Semantic transformations are observed when rendering resolute / negative advice or indignation. Why need we defend it? - Навіщо / чого це нам захищати це?

Need - бути повинним / мусити. Well, nobody needs know about it - Але ніхто не повинен знати про це.

Dare

a) Dare like verb need may function as a modal verb and as a regular finite verb. The translation remains the same - сміти, наважуватися, насмілюватися. She daren't come here when I was alone. - Вона не насмілювалася / сміла заходити сюди, коли я був сам.