Portico vs. veranda
The Italian words portico and veranda can both be translated as porch in English, but they describe distinct architectural features. The difference lies primarily in their structure, their level of enclosure, and whether they are typically found in public or private spaces.
Portico
A portico is a covered walkway, porch, or entrance where the roof is supported by columns or pillars. It is usually open to the outside air and is frequently found in historic public spaces, city streets, or as the grand entrance to a building.
Ci siamo riparati dalla pioggia sotto il portico.
(We took shelter from the rain under the porch.)
La città di Bologna è famosa per ogni suo antico portico.
(The city of Bologna is famous for each of its ancient porches.)
Il portico della chiesa offre un po' di ombra d'estate.
(The porch of the church offers some shade in the summer.)
Hanno costruito un piccolo portico davanti all'ingresso principale.
(They built a small porch in front of the main entrance.)
Gli studenti si incontrano spesso sotto il portico dell'università.
(The students often meet under the porch of the university.)
Veranda
A veranda is a roofed gallery or porch attached to the exterior of a residential house. Unlike a portico, a veranda is a private space designed for relaxation and is very often semi-enclosed or fully enclosed with glass windows, functioning as an extension of the indoor living space.
Abbiamo cenato in veranda guardando il tramonto.
(We had dinner on the porch watching the sunset.)
Mia madre ha riempito la veranda di piante tropicali.
(My mother filled the porch with tropical plants.)
La nuova casa ha una grande veranda chiusa da vetrate.
(The new house has a large porch enclosed by glass windows.)
Durante l'inverno usiamo la veranda come sala lettura.
(During the winter we use the porch as a reading room.)
Il cane dorme sempre sulla sedia a dondolo in veranda.
(The dog always sleeps on the rocking chair on the porch.)
Summary
To summarize, use portico when referring to an open porch or walkway supported by columns, which is often seen in public or historic architecture. Use veranda when talking about a private, residential porch that is frequently enclosed with glass and used as an extra living room.