A common pattern in Japanese is referring back to a noun that has already been mentioned, without actually repeating it. This is achieved through the use of the particle
の, in a similar way to its standard possessive use. The noun that would usually follow
の is dropped, as it has either been said earlier in the sentence, or is understood clearly from context.
In these examples, it would also be grammatically correct to use the same noun following
の, but as can be seen in the English translation, it results in unnecessary repetition. This is called word stacking/redundant words (重（かさ）ね言葉（ことば）) in Japanese, and is considered a poor writing/speech habit. Despite this, it is important to know that this
の is exactly the same as the possessive
の (with the following word simply being left out).
In the following sentence, we can see another common use of の that translates similarly to 'one' in English, when referring to non-specific things.
あの車（くるま）、あなたが乗（の）っているのですか。
That car, was it the car (one) you drove? ('Car' repeated, when の 'the one' should have been used instead)
From this, it is clear that the repeated noun is not needed. Japanese is a language that avoids repeating words in many situations. This example shows noun replacement, rather than noun omission, another common use of の which we will cover in another lesson.