Wikipedia:What you can do without English fluency

To contribute to the English Wikipedia, you have to have a basic understanding of English language and grammar. Otherwise, you might add incomprehensible text that other editors and readers can't understand, and may think constitutes vandalism. You might get blocked and lose your editing privileges. Here are things that you can do (and should not do) without being fluent in English.

Contribute to Wikipedia in a language that you know better
Wikipedia is available in many languages, and your native language will likely be there. A list of Wikipedias by language can be found here. Many smaller Wikipedias need help, and you can improve it. You can also contribute in a language you know better that is not your native language. For example, a person who is bilingual in Catalan (as a native language) and Spanish (as a second language) can contribute to the Spanish Wikipedia.

Contribute to the Simple English Wikipedia
The Simple English Wikipedia is an edition of Wikipedia that uses only basic words and grammar, and it may be easier for non-native English speakers to understand. Plus, there are many pages that need improvement or creation there.

Translate articles from a language you know better into English
Many articles on the English Wikipedia can be expanded with content from the same page in another Wikipedia. If you know basic English, you can translate articles and expand existing articles. The content translation tool can help with this, but it is only available to extended confirmed editors (500 edits and registered for 30 days).

Fight vandalism
You can fight vandalism on any language Wikipedia. Go to the recent changes page and search for any suspicious edits, check them out, and revert them if they constitute disruptive editing, vandalism, or any unconstructive edit. You can use tools like Twinkle to help with this.

Vandalize
Vandalism is not tolerated on Wikipedia, and you will be blocked if you continue to do it. It doesn't help the encyclopedia, and is arguably a waste of time. It will be reverted in a few minutes and you will be stuck with a warning on your talk page (unless you remove it, then it will be visible in the page history, or apply for oversight).

Continue to edit despite multiple warnings
If you continue to edit despite multiple warnings, you will eventually be blocked despite good intentions. Instead, you can file an edit request on the talk page of the article you want to be edited, and an editor will do it for you if the edit is constructive and acceptable. You should check the warnings on your talk page and avoid doing whatever it is that earned you that warning.

Learning English
Learning English may not be feasible for everyone, especially if you live in a non-English speaking country. There are plenty of resources online and offline to help you learn English, but it is your own choice.