Толщина стенок разная.

The thickness of the walls is uneven.

Breakdown of Толщина стенок разная.

• стена: the wall
• разный: different
• толщина: the thickness

Questions & Answers about Толщина стенок разная.

Why is there no word for is in this sentence?

Because Russian normally omits the verb to be in the present tense.

So:

• Толщина стенок разная. = The thickness of the walls is different.

But in the past or future, a form of быть appears:

• Толщина стенок была разной. = The thickness of the walls was different.
• Толщина стенок будет разной. = The thickness of the walls will be different.

This missing present-tense is is completely normal in Russian.

What case is стенок, and why is it in that case?

Стенок is genitive plural.

It is genitive because толщина usually takes the genitive to mean the thickness of something:

• толщина стенок = thickness of the walls
• compare:
  • длина кабеля = length of the cable
  • цвет двери = color of the door

So the structure is:

• толщина
  • genitive noun

That is why you get стенок here.

Is стенок from стена or стенка? What is the difference?