Thank you. So even in BrE the "to" is often omitted in casual speech.
Thank you for your explanation. But your comment "I wouldn't omit the "to" in formal writing/speaking or in an exam, but you'll hear it without "to" quite frequently." is more important to me because what I really wanted to know is whether I should teach the omission of the "to" in the sentence to Japanese high school students or not. The answer seems clearly to be 'No'.