diff --git a/source/introduction.md b/source/introduction.md
index 42bfca8a..c2011146 100644
--- a/source/introduction.md
+++ b/source/introduction.md
@@ -31,7 +31,7 @@ In the beginning of the game, you are free to choose the place for your new colo
 
 **![](img/colony-center.png)**
 
-**Energy sources** are the main game resource. They can be harvested by worker creeps. The amount of energy in a source is limited, but resumes once in 300 game ticks.
+**Energy sources** are the main game resource. They can be harvested by worker creeps. The amount of energy in a source is limited, but regenerates once every 300 game ticks.
 
 **Spawns** are your colony centers. They can accumulate mined energy and use it to create your units. There may be no more than 3 spawns in a room. Hence, by building 3 spawns in a room you actually conquer it. You can have multiple spawns totally in all your rooms though.