The use of the definite article with nouns in set expressions.

1. it is out of the question — об этом не может быть и речи

"Will you go to the theatre tonight?" "It's out of the question. I have lots of things to do."

2. to take the trouble to do something — потрудиться

You had a difficult text to translate and you did not take the trouble to consult the dictionary.

3. in the original — в оригинале

You know English well enough to read Dickens in the original.

4. to play the piano (the violin, the harp) — играть на рояле (скрипке, арфе)

She plays the piano very well.

5. at the end of the day — в конце концов

At the end of the day it doesn't matter.

6. at the beginning — вначале

He looked very self-conscious at the beginning.

7. on the whole — в целом

On the whole Tom is a pleasant fellow, but sometimes he has whims.

8. the other day (refers to the past) — на днях

I met him the other day.

9. on the one hand... on the other hand — с одной стороны... с другой стороны

On the one hand he certainly excites suspicion, but on the other hand we have not enough evidence against him. (Oppenheim)

10. to tell (to speak) the truth — говорить правду; to tell the truth — по правде говоря

He always speaks (tells) the truth. To tell the truth, I don't like the girl.

11. to be on the safe side — для верности

I am almost sure of the pronunciation of this name, but to be on the safe side let us consult the pronouncing dictionary.