i have a question regarding to problem in excel please help me.

here is the example for each cells:
a2= en
a3=engli
a4=english
a5=englishia

b1= i want to learn english.

my question is:
how to make excel calculate how many times the word (english) in b1 appears in each cell? i dont want to see it calculated in other cells even missing letters.
for example like i want to see...b2= 0 , b3= 0 , b4= 1 , b5= 0 .
what is the formula please?
thank you