Одним жестом учитель попросил нас помолчать.

the teacher

Breakdown of Одним жестом учитель попросил нас помолчать.

• нас: us
• один: one
• попросить: to ask

Questions & Answers about Одним жестом учитель попросил нас помолчать.

Why is одним жестом in the instrumental case?

Because the instrumental case is often used to show the means or method by which something is done.

So одним жестом means with one gesture or by a single gesture.

• жест = gesture
• жестом = by/with a gesture
• одним agrees with жестом in case, number, and gender

This is very common in Russian:

• одним словом = with one word
• взмахом руки = with a wave of the hand

So the phrase tells you how the teacher asked: not by speaking, but by making a gesture.

What form is одним here?

Одним is the instrumental singular form of один.

Here it agrees with жестом, which is masculine singular instrumental.

The forms are:

• nominative masculine: один
• instrumental masculine/neuter: одним

So:

• один жест = one gesture
• одним жестом = with one gesture

Even though one is a number in English, in Russian один behaves much like an adjective, so it changes form to match the noun.

Why is учитель in this form?