Let's consider the present tense of a regular "ir" verb. The verb meaning (to live) in Spanish is vivir.

Take off the -ir ending:
vivir - ir = viv

Now we add on one of the present tense endings:

viv + (ending) --> vivo, vives, vive, vivimos, vivís, viven

Let's look at some example sentences:

Vivo en Londres.
I live in London. (I am living in London.)

¿En dónde vives?
Where do you live?

¿En qué ciudad vive usted?
What city do you live in?

¿En qué condado vive usted?
What county do you live in?

Mi hermano mayor vive en Chicago.
My older brother lives in Chicago.

Mi primo vive en Londres.
My cousin (male) lives in London.