Can I try these on?
'Provare' — 'pro-VA-re'. Stress on the second syllable. 'Questi' = 'KWES-ti'.
Pointing to shoes you'd like to try. The most common sentence in any shoe shop. Always try before buying — Italian shoes vary in fit between brands.
'Posso' (can I) + infinitive for permission. 'Questi' = these (masculine plural, referring to shoes — 'le scarpe' is feminine but you're pointing to the display pair, often treated as masculine objects).
Vorrei provare queste scarpe.
I'd like to try these shoes.
More polite conditional + explicitly naming 'shoes'
Posso provarle?
Can I try them on?
'Le' refers back to 'le scarpe' (feminine) — correct pronoun
Mi fa vedere queste nella mia misura?
Can you show me these in my size?
Asking staff to fetch the right size specifically
Italian shoe shops ('calzolerie') often keep display shoes in the window or on open shelving. The stockroom ('magazzino') holds the full range. Staff fetching sizes from the back is standard — don't feel you're inconveniencing anyone.