strings and expressions

[taciturn]

Hi, I've never really gotten the hang of strings and expressions.
only used a little like random and retrive data. But is there any list of all expressions that can be used somewhere? Havn't been able to find anything, and the F1 seem to only have a few of those I've seen.
How do all people learn those weird strings some use?

[Werbad]

They are all under retrieve data from an object or any of the buttons at the bottom. Most commonly used formulas go under the special object.