Which word do you use ??
As I typed a message this morning I used the phrase " font of knowlege"......then after sending it I wondered if it should have been " fount of knowlege".
After some researching I discovered that there are many words like this that can be interchanged and are commonly used.
One that got my attention was " free rein" or " free reign".
It would seem that they have different meanings......a free rein would suggest that you are giving full freedom to whomever.
Free reign, on the other hand , suggests that the person has complete authority or control over the situation.
In my way of thinking, there is a very slight difference in the connotation.
I'm sure that there are many other words such as these which give us pause.