Formatting

subjects/doop.en.md

@@ -10,9 +10,9 @@ Write a program that takes three strings:
 
 - The program must display the result of the requested arithmetic operation, followed by a newline. If the number of parameters is not 3, the program just displays a newline.
 
-- You can assume the string have no mistakes or extraneous characters. Negative numbers, in input or output, will have one and only one leading `-`. The result of the operation fits in an int.
+- During tests the strings will have no mistakes or extraneous characters. Negative numbers, in input or output, will have one and only one leading `-`. The result of the operation will fit in an int.
 
-Example of output :
+Examples of outputs :
 
 ```console
 student@ubuntu:~/piscine/test$ go build