diff --git a/lang/Solidity.wiki b/lang/Solidity.wiki
index f4becf8..1d7db67 100644
--- a/lang/Solidity.wiki
+++ b/lang/Solidity.wiki
@@ -3,5 +3,21 @@
 Solidity is a language used for smart contracts on several blockchains,
 including ethereum.
 
+== Structure ==
+
+It is a good guideline to strcutre functions that interact with other contracts
+in three phases
+
+1) check conditions
+2) perform actions (possibly changing the conditions)
+3) Interact with the other contract
+
 
 == Keywords ==
+
+- external 
+  - applies to a function
+  - allows the function to be called from outside of the contract
+- payable 
+  - applies to a function
+  - allows the function to recieve Ether