We saw that generally nouns ending with " - o " are masculine and those ending with " - a " are feminine.

Then there are the nouns that end with " - e ". You just saw "stazione," "ospedale," and "ristorante."

Nouns ending with " - e " can be either masculine or feminine: stazione is feminine, ospedale and ristorante are masculine.

Stazione will take a feminine article (una stazione) and ospedale and ristorante will have masculine articles (un ospedale, un ristorante).

Similarly, adjectives will have to agree with the gender of the noun:
un ristorante italiano
una stazione famosa

There are some clues to tell the gender of some of the nouns ending with " - e ", but in the majority of the cases there is no way to know : you will have to memorize it (it is much easier than it seems.)

TIP
Always memorize the article together with the noun. It will be easier to remember the gender, masculine or feminine, of that word.

Per
(for)

Per chi lavori tu?

UNO

is the form of the indefinite article  in front of masculine nouns that begin with:

1) s- followed by another consonant (sc, st, sv, sn, etc.)

scavo (dig)
stadio (stadium)
studente (student)
sventato (absent minded).......

2) z-

zero
zingaro... (gipsy).

3) gn- (rare)

gnomo... (dwarf)

4) ps -

psicologo, psichiatra...(psychologist, psychiatrist)

5) pn- (very rare)

pneumatico (car tire)

Normally adjectives that describe a quality follow the noun they are associated with: un uomo famoso, una casa confortevole.

You should be aware that several of the most common adjectives, such as grande, piccolo, bello, brutto (ugly), buono, cattivo (bad) often precede the noun: una bella casa, un piccolo appartamento.

This is not a "grammar rule," it is the way people speak, but they will understand you whichever word order you use. So, it also correct to say una casa bella, un appartamento piccolo.

The interactive exercises below allow you to use either word order.