You can add or remove multiple speaking languages in your profile as per your choice but only use the languages according to your perfection level in that. A student can search tutor in listing according to the tutor's speaking language.
Follow these steps to manage speaking language:
Login>profile>teaching details>add or remove language>save!
Click on the Profile button
Go to the 2nd section Teaching details, in this section, you can add or remove tutor speaking languages
Save the changes.