Emphasis

Do: used for emphasis with answers, statements and negative answers in the past and present tenses
They cleaned the room. – They did clean the room.
She speaks English. – She does speak English.
Do/does/did + verb
I like coffee. – I do like coffee.

it is/was … who/that
It was that rain that ruined our plans
It was Prof. Adams who proposed such an interpretation.
It is an EFL teacher who can predict students' difficulties

1. It is these special properties of sound that are the subject of the present chapter.
2. But it is not the chairperson who is the central figure of that meeting.
3. It is no doubt to this quality that the great popularity of this collection is due.
4. It is that task — that imperative to make Harvard even better—that brings us together this weekend.
5. It is this language that enables us to communicate with each other.
6. It was the Dutch physicist, Christian Huygens, who first offered an explanation for the phenomena.

What + sentence
You need a day off. – What you need is a day off.
I don't like his ignorance. – What I don't like is his ignorance.

It was not until … that …
(Временная рамка)
It was not until 1911 that the first satisfactory theory of the atomic structure was formulated.
И только в 1911 году была сформулирована первая удовлетворительная теория структуры атома.

so … that/such … that.
Her speech was so awesome
So awesome was his speech that I asked him to read it one more time.
Such was her argument strong that we had to agree
После such сразу будет глагол и подлежащее. Прилагательное или наречие здесь не нужны. Обычно по контексту предложения понятно, какое качество подразумевается.

Наречия частоты действия (hardly/barely/scarcely – едва ли, never – никогда, rarely/seldom – редко, no sooner … than – не успел … как).
I have never seen such a beautiful child
Never have I seen such a beautiful child.
Hardly ever does she listen to her students
She never listens to her students