Learning to write and speak a foreign language correctly requires having somebody to correct your grammar and usage errors.
Otherwise you may learn a substandard version of the language with deep-rooter mistakes and incorrect usages that are hard to get rid of.
A popular and tried-and-true way to learn languages involves writing texts in a foreign language on a daily basis and reading them aloud to a native speaker, who will correct any mistakes.
Native speakers or language professionals will review your text and correct all errors of style or grammar free of charge.
You can also request a sound recording of the spoken version of your corrected text that will let you hear the subtleties of pronunciation by a native speaker.