Grande vs. grosso

The Italian words 'grande' and 'grosso' both translate to 'big' in English, but they have distinct uses and connotations in Italian.

Grande

'Grande' generally means 'big' in terms of importance, significance, or quality. It can also refer to physical size, especially height or length.
Quello è un grande attore.
(That is a great actor.)
Roma è una grande città.
(Rome is a big city.)
Ho un grande rispetto per lei.
(I have great respect for her.)

Grosso

'Grosso' typically refers to physical size, particularly in terms of volume, thickness, or bulkiness. It can sometimes have a negative connotation, implying clumsiness or lack of refinement.
Quel cane è molto grosso.
(That dog is very big.)
Ho fatto un grosso errore.
(I made a big mistake.)
Questo è un grosso problema da risolvere.
(This is a big problem to solve.)

Summary

While both 'grande' and 'grosso' mean 'big', 'grande' is often used for abstract concepts or positive attributes, and can refer to height or length. 'Grosso', on the other hand, typically describes physical bulk or volume and can sometimes carry a less favorable implication.