Rule reminder
'Comprare' = to buy (everyday, colloquial — by far the most common in speech). 'Acquistare' = to purchase (formal/commercial register — used in shops, contracts, advertising, financial contexts). 'Acquistare' can also mean 'to gain' (e.g., acquistare fiducia = to gain trust) — a meaning 'comprare' does not have.
Sono andato al supermercato a _____ il latte e il pane.