I have a 3 year old and a 14 month old and they’re the same way. I tell them that they need to share and to give it back. If they don’t then I take that toy away for the rest of the day.
@Indigo yes I take the toy away but then they fight about something else - exhausting
I have this issue with my toddler except it’s his puppy brother he keeps hitting and honestly I have to put the toddler in time out multiple times a day but I do think time out works best