Update instructions.md

exercises/concept/meteorology/.docs/instructions.md

@@ -3,7 +3,7 @@
 Your team is working on a meteorology application. 
 They have defined an API with various types and constants representing meteorological data, see file `meteorology.go`. 
 
-Your task is to add suitable `String` methods all types so that they implement interface `Stringer`. 
+Your task is to add suitable `String` methods to all types so that they implement interface `Stringer`. 
 
 Values should be formatted as in the examples below: 
 
@@ -31,5 +31,5 @@ fmt.Println(metData)
 
 In the test data, you can assume that
 
-- the unit of temperature be either `Celsius` or `Fahrenheit` 
+- the unit of temperature will be either `Celsius` or `Fahrenheit` 
 - the unit of wind speed will be either `KmPerHour` or `MilesPerHour`