The best way to learn a language is to speak the language.
The best way to learn a language is to speak it.
The best way to learn a language is by speaking the language.
The best way to learn a language is by speaking it.
The two sentences ending with "the language" are grammatical, but they are also awkward and stilted. The other two ending in "it" are - strictly speaking - not grammatical because they end with a preposition. The "rule" about ending a sentence with a preposition is fast becoming obsolete and I have no problem with the sentences above.
The two sentences ending with "the language" are grammatical, but they are also awkward and stilted. The other two ending in "it" are - strictly speaking - not grammatical because they end with a preposition. The "rule" about ending a sentence with a preposition is fast becoming obsolete and I have no problem with the sentences above.
Anyone who posts in this forum, whatever their 'rank' does so in the knowledge that others can question/correct their answers; that is one of the great things about it.