Breakdown of У гигантской рептилии был хвост длиной в десять метров.
десять
ten
у
at, by
быть
to be
метр
metre
Questions & Answers about У гигантской рептилии был хвост длиной в десять метров.
Why is the Russian word for length, длина, in the Instrumental case (длиной)?
When you describe the physical dimensions of an object, such as length, width, or height, the dimension noun is put into the Instrumental case to act as a modifier. So хвост длиной... translates conceptually as a tail by length...
How does the phrase в десять метров work grammatically here?
This is the core of your current lesson! To state the actual measurement, you use the preposition в followed by the Accusative case. Here, the number десять is in the Accusative (which looks identical to the Nominative for this number), and as usual, it forces the noun being counted, метров, into the Genitive plural.
Do I always have to use в when stating a dimension like this?
Not always. In everyday spoken Russian, the в is frequently dropped, and you will just hear хвост длиной десять метров. However, keeping в + Accusative is the formally correct, traditional structure that you are practicing in this lesson.
Is there another common way to say a ten-meter tail in Russian?