Can I say "I missed you" instead of "I have missed you" here?

Native speaker’s answer
Rebecca
Yes, that's correct. "I missed you" can be used here instead of "I have missed you." "I have missed you" is a more old-fashioned way of speaking and is more formal in tone, whereas "I missed you" is more casual and modern. In casual conversation today, most people would say "I missed you" without using "have." Ex: I missed you so much! I'm glad you're back. Ex: I have waited for your return. => I waited for you to return. (Formal vs. informal)