I'll tell you what
US /aɪl tɛl ju wʌt/
UK /aɪl tɛl ju wʌt/

1.
te diré una cosa, sabes qué
used to introduce a suggestion or a solution to a problem
:
•
I'll tell you what, let's just order pizza tonight.
Te diré una cosa, pidamos pizza esta noche.
•
You're struggling with that? I'll tell you what, I can help you.
¿Estás luchando con eso? Te diré una cosa, puedo ayudarte.