I think the most effective way to learn a new language is through consistent practice and immersion.
A) I believe the most effective way to learn a new language is through consistent practice and immersion.
B) I know the most effective way to learn a new language is through consistent practice and immersion.
C) I doubt the most effective way to learn a new language is through consistent practice and immersion.
D) I am sure the most effective way to learn a new language is through consistent practice and immersion.
