Italian normally uses essere to say where something is.
A learner may wonder about stare, because it can sometimes be used for location in Italian, especially in everyday speech or in some regions. But essere is the most neutral and standard choice here.
Yes, adverbs like sicuramente can often move around in Italian, though the emphasis changes a little.
This sentence:
is very natural.
Other possible versions include:
These all mean roughly the same thing, but the focus shifts a bit:
The version in your sentence is a very normal, smooth word order.
Here ancora means still.
It shows that the situation continues: the phone was inside before, and it is inside now as well.
This is important because ancora can also mean again in other contexts.
For example:
So the exact meaning depends on context. In your sentence, it clearly means still.
Because ancora modifies the whole idea of the phone being inside. It tells you that the state of being inside continues.
So:
That is the most natural order here. A version like è dentro ancora is possible in some contexts, but it is less neutral and can sound marked or less natural.
Here dentro is being used as an adverb, meaning inside or in there.
It does not name the place explicitly. Italian can do this when the place is already understood from context.
For example, if people are talking about a bag, a room, a drawer, or a house, dentro can simply mean inside it / in there.
So the sentence does not need to say inside what if that is already clear.
Yes. Dentro can also be followed by a noun phrase when you want to say what something is inside.
For example:
But when the place is obvious from the situation, Italian often just says dentro.
It is a very normal Italian order.
The sentence builds like this:
So the sentence moves from:
That order sounds natural and clear in Italian.
It sounds completely natural.
A speaker might stress different words depending on what they want to emphasize:
The basic meaning stays the same, but spoken emphasis can highlight:
So even though the grammar is simple, intonation can add nuance.