Hi Natasha,
Generally speaking, under appropriate conditions:
1. alcohol + aldehyde or ketone (under base conditions) --> hemiacetal/ketal
2. alcohol + aldehyde or ketone (under acid conditions) --> hemiacetal/ketal OR acetal/ketal
3. alcohl + carboxylic acid (under acid conditions) --> ester (Fischer esterification)
I hope this helps,
Katt