Sento il profumo dei fiori in giardino.

In Italian sentire covers all five senses, so sento can mean “I hear,” “I feel,” “I taste,” and “I smell.”

• Annusare and fiutare both imply actively sniffing or tracking a scent.
• To express a general perception of fragrance, Italians prefer sentire il profumo.

Italian nouns almost always require a definite article:

• Il profumo (“the fragrance”) refers to that specific scent you’re perceiving.
• Dropping il (saying sento profumo without any article) sounds unnatural or overly generic in everyday speech.

Dei is the contraction of di + i (“of the,” plural masculine). We use it because fiori is masculine plural.

• delle would pair with feminine plurals (e.g., delle rose).
• You could use just di (“profumo di fiori”), but that’s more poetic or indefinite. Profumo dei fiori clearly means “the fragrance of the flowers.”

Certain locations in Italian drop the article after common prepositions:

• in giardino (“in the garden”)
• a casa (“at home”)
• a scuola (“at school”)
  Saying nel giardino focuses on a specific garden (“inside the garden we fenced”), while in giardino is the idiomatic way to state the location in general.

Yes.

• Sento un buon profumo = “I smell a nice fragrance” (more general).
• Sento il profumo dei fiori = “I smell the fragrance of the flowers” (specific source).

Absolutely. Italian word order is flexible:

• Sento il profumo dei fiori in giardino
• In giardino sento il profumo dei fiori
  Both are correct; placing in giardino first emphasizes the location.

Dei comes from di + i. Italian contracts di with articles as follows:

• di + il → del
• di + lo → dello
• di + la → della
• di + l’ → dell’
• di + i → dei
• di + gli → degli
• di + le → delle
  These mean “of the” and match gender and number of the noun.