Formal:
* É? (pronounced "Eh?") - This is the most common and neutral way to say "Is it?"
* Será? (pronounced "seh-rah?") - This is a slightly more formal way to say "Is it?" and implies a sense of uncertainty.
Informal:
* É isso? (pronounced "eh ee-so?") - This means "Is that it?" and is more informal.
* É que...? (pronounced "eh keh...") - This is used when you are asking for confirmation or clarification, similar to "Is it that...?"
Examples:
* Você está bem? É? (Are you okay? Is it?)
* Essa é a sua casa? Será? (Is this your house? Is it?)
* Você quer ir ao cinema? É isso? (You want to go to the cinema? Is that it?)
* É que você não me respondeu. (Is it that you didn't answer me?)
The best translation will depend on the specific context and your level of formality.