Write Multiple Languages on Each Page
For small collections of documentation, or pages where you won't translate much content, writing all languages on one page may be an option.
With this approach, you will want to clearly separate different languages on the page so your readers can quickly find their preferred language and skim for information.
To separate each language on a page, you can do a few different things:
Use headings for each language in that language
If there is a primary language with small snippets of other languages within the content, you could put those snippets in a Panel macro to visually separate it from the surrounding content.
Hide the content for the different languages within Expand macros so users can view their chosen language only.
Keep in Mind
This approach keeps all content together on one page, which helps your team in the authoring process.
The user experience on these pages won't be great, since users need to skim to find their preferred language.
Your team must be careful to update all languages on each page manually.
This approach requires you to do all translation in Confluence, and doesn't support working with an external Translation Management System.