Update instructions.md

exercises/concept/annalyns-infiltration/.docs/instructions.md

@@ -6,9 +6,9 @@ After some time spent following her best friend's trail, she finds the camp in w
 
 Having found the kidnappers, Annalyn considers which of the following actions she can engage in:
 
-- Fast attack: a fast attack can be made if the knight is sleeping, as it takes time for him to get his armor on, so he will be vulnerable.
+- Fast attack: a fast attack can be made if the knight is sleeping, as it takes time for him to get his armour on, so he will be vulnerable.
 - Spy: the group can be spied upon if at least one of them is awake. Otherwise, spying is a waste of time.
-- Signal prisoner: the prisoner can be signalled using bird sounds if the prisoner is awake and the archer is sleeping, as archers are trained in bird signaling, so they could intercept the message.
+- Signal prisoner: the prisoner can be signalled using bird sounds if the prisoner is awake and the archer is sleeping, as archers are trained in bird signalling, so they could intercept the message.
 - _Free prisoner_: Annalyn can try sneaking into the camp to free the prisoner.
   This is a risky thing to do and can only succeed in one of two ways:
   - If Annalyn has her pet dog with her she can rescue the prisoner if the archer is asleep.