Learn Italian: La periferia è tranquilla, ma il centro è rumoroso. - The outskirts are quiet, but the center is noisy.

In Italian, la periferia is a singular noun meaning the outer ring or suburbs of a city. Because it is singular, it uses the singular verb è (is) and the singular adjective tranquilla. English just happens to use a plural word ('outskirts') for the same idea.

Why does tranquilla end in -a while rumoroso ends in -o?

Adjectives in Italian must match the gender of the noun they describe. La periferia is feminine, so it gets the feminine ending -a in tranquilla. Il centro is masculine, so it gets the masculine ending -o in rumoroso.

How would I say 'the center is the noisiest' using the relative superlative from this lesson?

You would say il centro è il più rumoroso. To form the relative superlative ('the most...'), you combine the definite article (il), the word più (more/most), and the adjective (rumoroso). If you wanted to say 'the outskirts are the quietest', it would be la periferia è la più tranquilla.

Does il centro strictly mean the geographic center of a place?