Some minor corrections I found during a new playthrough.
1) Letter from grandpa (prologue):
"If Lewis is still alive say hi" --> "If Lewis is still alive, say hi"
2) Robin during prologue:
"This is [FARMNAME] farm." --> "This is [FARMNAME] Farm." (should be capitalized imho as it's treated as part of the name)
3) Robin during prologue:
"...And here we are, your new home." --> "...And here we are: your new home."
4) Lewis during prologue
"Welcome! I'm Lewis, Mayor of Pelican Town." --> "Welcome! I'm Lewis, mayor of Pelican Town."
5) Description "Oil"
"All purpose cooking oil." --> "All-purpose cooking oil."
6) Description "Wood"
"A sturdy, yet flexible plant material [...]" --> "A sturdy yet flexible plant material [...]"
7) Description "Garlic"
"High quality garlic" --> "High-quality garlic"
8) Description "Summer Squash"
"[...] harvested while immature, and still tender." --> "[...] harvested while immature and still tender."
9) Description "Dressed Spinner"
"Increases the bite-rate when fishing." --> "Increases the bite rate when fishing."
10) Journal Description "A Winter Mystery"
"You encountered a suspicious looking figure by the bus stop." --> "You encountered a suspicious-looking figure by the bus stop."