You just forgot one thing.

You just forgot one thing. I saw everything that happened. And I'm going to tell on you if you mess with me. / Ты кое-что забыл. Я все видел. И я все расскажу, если ты будешь со мной шутить.

I learned something today.

We have something very important to discuss.

I thought of something.

I have something that might interest you.

- I have something that might interest you. / У меня есть кое-что, что может вас заинтересовать.

- What is it? / Что это?. 

- I can tell you that on the phone. I'll show you when we meet in person. / Я не могу вам сказать по телефону. Я покажу вам при личной встрече.

Let me grab something real quick.

I learned something too.

I've got something planned.

Can I make a suggestion?

Can I get you to do something for me?