Answer:
Here you go, alter this as you see fit :)
Step-by-step explanation:
array = []
cnt = 0
while cnt < 11:
x = input("Enter a word: ")
array.append(x)
cnt += 1
y = input("Add another word?(Y/n): ")
if y.lower() == "n":
break
letter = input("\\Choose a letter: ")
if len(letter) != 1:
print("Error: too many characters")
quit()
for n in range(len(array)):
if letter.lower() in array[n].lower():
print(array[n], end= ",")