Learn Spanish (Latin America): Hay una televisión en la sala. - There is a television in the living room.

We use hay (there is) because we are talking about the existence of an unspecific object. We are just saying that 'a television' exists in the room. If we were talking about a specific television, like 'the television is in the living room', we would use está (La televisión está en la sala).

Why is it una televisión? Aren't words ending in -ón usually masculine?

While some words ending in -ón are masculine, Spanish words that end specifically in -ión (like televisión, canción, or estación) are almost always feminine. That is why we use the feminine article una.

Could I use the word televisor instead of televisión?

Yes! El televisor refers specifically to the physical device (the TV set), while la televisión can mean either the physical device or the TV programming itself. In everyday conversation, people often use televisión (or just la tele) for the physical TV, so this sentence is very natural.

Does the word en mean 'in' or 'on'?