Ang eSIM ay nasa telepono.

No. Ay is not a verb meaning is. It is a marker used in the pattern topic + ay + predicate.

So in Ang eSIM ay nasa telepono, ay is linking Ang eSIM to the rest of the sentence. It does not itself mean is.

This sentence is a good example of a non-verbal sentence. Filipino often does not need a separate verb like English is in simple statements of identity, description, or location.

Here, nasa telepono functions as the predicate and tells you the location.

Nasa is used for location. Depending on context, it can mean is in, is on, or is at.

In this sentence, it means the eSIM is located in the phone.

Sa by itself is a very common marker for location or direction, often corresponding to to, in, on, or at in English.

But when you want to say that something is located somewhere, Filipino commonly uses nasa. So nasa telepono is the natural way to say is in the phone here.

Yes. Nasa telepono ang eSIM is completely correct and often sounds more natural in everyday speech.

The version with ay—Ang eSIM ay nasa telepono—is also correct, but it can sound a bit more formal, written, or topic-emphasizing.

Filipino markers like ang, ng, and sa are used with nouns no matter where those nouns come from. A borrowed or technical word can still be marked normally in Filipino.

So ang eSIM is perfectly natural grammatically.

No. Nasa is broader than English in. The exact English preposition depends on the situation.

For example:

• Nasa bahay siya = He/She is at home
• Nasa mesa ang susi = The key is on the table
• Nasa telepono ang eSIM = The eSIM is in the phone

So English chooses in, on, or at, while Filipino often uses nasa for all of these location meanings.

A common pronunciation is te-le-PO-no, with the stress on PO.

A few other helpful pronunciations from the sentence:

• ang ≈ ahng
• ay ≈ eye
• nasa = NA-sa

For eSIM, many speakers use an English-style pronunciation, so you may hear ee-sim.