Sometimes it's more convenient for me to use Blender in another language. Does Blender have different languages (language as in speech language as english, not computer language as python)?
Yes you can change the default interface language in blender.
To do so open the User preferences, go to the system tab, on the bottom right of the screen there is a checkbox that says "International Fonts" check it then select one of the translations then choose to apply it to "Interface" or "Tooltips" or both.
In Blender 2.8x to 2.9x the language/translation preferences can be found in Edit > Preferences > Interface > Translation.
The translation can be selectively applied to different parts of the UI as explained in the manual:
Tooltips Translates the descriptions when hovering over UI elements.
Interface Translates all labels in menus, buttons, and panels.
New Data Translates the names of new data-blocks.