Не нашли символ, не говоря уже о потайной двери.

Russian often leaves out subject pronouns when the context already makes them obvious. So не нашли can mean they didn’t find, we didn’t find, or even a more general the searchers didn’t find, depending on the situation.

The form нашли is the past tense plural of найти. Russian past tense agrees with the subject in gender/number, so plural tells you the missing subject is plural.

Нашли is from the perfective verb найти, which focuses on the result: after searching, the result was failure to find it.

So не нашли means something like did not succeed in finding.

If you used не находили instead, that would usually sound more like:

• they were not finding it
• they did not find it on repeated occasions
• in general, they never found it during some period

Here the sentence is about a concrete unsuccessful result, so не нашли is the natural choice.

This is a very common question because Russian negation can allow either accusative or genitive with a direct object.

In modern Russian, не нашли символ is very normal, especially when the object is viewed as a specific, concrete thing they were trying to find.

Не нашли символа is also possible, but it can sound a bit more indefinite, abstract, or stylistically marked in some contexts.

So here the accusative символ suggests a fairly definite target: they were looking for a particular symbol and did not find it.

Because it is a masculine singular inanimate noun.

For many masculine inanimate nouns, the accusative singular is identical to the nominative singular. So:

• nominative: символ
• accusative: символ

That is why after не нашли you still see символ.

Говоря is the adverbial participle (Russian: деепричастие) of говорить.

Very roughly, adverbial participles often correspond to English ideas like:

• while speaking
• speaking
• by saying

But in this sentence, it is best to learn не говоря уже о as a fixed expression rather than trying to translate говоря word by word every time.

It is a fixed expression meaning:

• let alone
• never mind
• not to mention

It introduces something even more unlikely or difficult.

So the logic is:

• they didn’t even find the symbol,
• let alone the hidden door.

Literally, the words are closer to not speaking already about..., but that literal version is not how you should understand it in normal English. Treat the whole phrase as one idiom.

Because не говоря уже о... comes from an adverbial-participle construction, and those are normally set off by commas in Russian.

In practice, this whole phrase behaves like a fixed inserted expression, so the comma is standard:

• Не нашли символ, не говоря уже о потайной двери.

The preposition о in the sense of about requires the prepositional case.

So:

• дверь becomes двери
• потайная becomes потайной

That gives:

• о потайной двери = about the hidden door

Even though двери can also be a plural form in other contexts, here it is singular prepositional, because it follows о and agrees with потайной.

You do not know from the noun form alone, because Russian has no articles.

Russian simply says символ, and English has to choose a or the from context. If the symbol has already been mentioned or is understood to be a specific one, English will usually say the symbol.

So article choice is something you infer, not something Russian marks directly.

Потайной means hidden, concealed, or secretly built in.

A потайная дверь is usually a door that is physically disguised or concealed, like a hidden panel door in a wall or bookcase.

So it is a very natural adjective for a secret door in the architectural or physical sense.

Yes. Russian word order is flexible, and different orders can shift emphasis.

This version:

• Не нашли символ, не говоря уже о потайной двери.

is natural and fairly neutral.

But you could also see something like:

• Символ не нашли, не говоря уже о потайной двери.

That would put extra focus on символ.

So the core meaning stays the same, but the information focus can change.