disagree

profoundly, sharply, strongly, vehemently

My parents and I strongly disagree about whether I should study abroad next year.

completely, entirely, totally

My brother and I completely disagree about which restaurant to choose for dinner tonight.

be difficult to, be hard to, can/could hardly

It would be hard to disagree that learning English takes time and patience.

about

My parents often disagree about how to spend money on household expenses.

on

My parents disagree on whether I should study abroad next year.

over

The family disagreed over where to spend their summer vacation.

with

My brother and I often disagree with each other about which films to watch.