1)

a)I used to play football.

b)I was used to play football.

2)

a)I have heard this song.

b)I heard this song.

Is the thought below correct?

Our teacher's mother is a teacher.

The sentence above means "The mother of our teacher is a teacher", right?
bassa1)
a)I used to play football.
b)I was used to play football.
I've never heard (b). Perhaps you're thinking of "I was used to playing football."
"I used to do X." = "In the past, I [often] did X."

"I was/am used to doing X." = "I was/am accustomed to doing X." (It was/is natural for me.)
bassa2)
a)I have heard this song.
b)I heard this song.
Example (b) means that you heard it one time in the past.

Example (a) means that you heard it in the past at least one time, and possibly multiple times.
bassaIs the thought below correct?
Our teacher's mother is a teacher.
The sentence above means "The mother of our teacher is a teacher", right?
Right!

And it's correct.
Thansk Emotion: smile

On number tree the mother is a teacher, right?
Students: We have free audio pronunciation exercises.
bassaOn number tree the mother is a teacher, right?
Yes, the mother is a teacher.
Thanks Emotion: smile