When to use Que

Question

When saying "I would like to tell you something", I originally said "Tengo algo decirte". A fluent speaker corrected me to say "Tengo algo que decirte". Why is th "que" used in this sentance? That translates "I have something that/what to tell you." Could someone explain this rule to me?

Answer 1

Long story short...Spanish is complex

The 'que' is used in reference to the information that you want to say.

So the 'que' in "Tengo algo que decirte" is used to mean "There is something that I would like to tell you"

Answer 2

So how do u know when to use it? I undertstand that it dosnt translate directly; however, Is there a rule or a semi-rule i can follow? Any guide in the right direction to a rule would be very helpful because if not I will never truely know if I should pu the "que" or not.