The Moscow underground transportation system is the deepest one in the world.
We would never have expected that.
You have to listen carefully and you repeat.
If you don't use it anymore for 10 years or longer, you will not forget it.
Being a bilingual was really helpful in learning my first language.
I'm only scratching the surface here.
What do I mean by that?
PRESENT SIMPLE
MODAL FOR OBLIGATION
PAST MODAL
SUPERLATIVE FORM
GERUND
FIRST CONDITIONAL (Present Real Conditional)
PRESENT CONTINUOUS