If you can write your posts in 2 or more(Woo…) languages within one blog, you might want to tell the client browser the language attribute of you posts.
According to <a href="http://www.w3.org/International/tutorials/language-decl/en/all.html" title=" W3C tutorial" rel="nofollow ugc">the tutorial on W3C</a>, language attribute can be declared in the container html tag of your post like this: 
<div id=”post_id” class=”post_entry” lang=”zh-Hant” xml:lang=”zh-Hant” dir=”ttb”>… 
Here “zh-Hans” is the language attribute of your post which means it’s written in Simplified Chinese.
This plugin gives your post a language tag by adding a meta deta to that post.
To add language tag, select it from the language box when you compose/edit a post. Select “None” will delete the language tag.
<h3>Revisions</h3>
2007-12-18, 
0.2: Now you can difine language direction. 
 Insert CSS style into page head automatically to support pretty printing.
 readme file updated for new feature and fixed a error
2007-07-23 
0.1: First release

Multilingual post

This plugin adds a standard compliant language tag to your post and page.

Takayuki Miyoshi

Umar Draz

Rock Lobster Inc.

Bogo is a straight-forward multilingual plugin for WordPress.
The core of WordPress itself has the built-in localization capability so you can use the dashboard and theme in one language other than English. Bogo expands this capability to let you easily build a multilingual blog on a single WordPress install.
Here are some technical details for those interested. Bogo plugin assigns <a href="https://wordpress.org/support/article/multilingual-wordpress/#different-types-of-multilingual-plugins" rel="ugc">one language per post</a>. It plays nice with WordPress – Bogo does not create any additional custom table on your database, unlike some other plugins in this category. This design makes Bogo a solid, reliable and conflict-free multilingual plugin.
<h4>Getting started with Bogo</h4>
<ol>
<li>
Install language packs
First, install language packs for languages you use on the site. You can view and install language packs in the Language Packs screen (Languages > Language Packs).
</li>
<li>
Select your language for admin screen
Bogo lets each logged-in user select a language for their admin screen UI. Select a language from the menu on the <a href="https://wordpress.org/support/article/administration-screens/#toolbar-keeping-it-all-together" rel="ugc">Toolbar</a>, or from the menu in the Profile screen (Users > Your Profile) if the Toolbar is invisible.
</li>
<li>
Translate your posts and pages
To create a translation post, go to the editor screen for the original post and find the Language box. Bogo does only make a copy of the post; translating the copied post is your task.
</li>
<li>
Add language switcher widgets
It would be useful for site visitors if you have a language switcher on your site. Bogo provides the Language Switcher widget in the Widgets screen (Appearance > Widgets).
You can also use the <code>[bogo]</code> shortcode to put a language switcher inside a post content. If you want to use this shortcode in your theme’s template files, embed the following code into the template:
<pre><code><?php echo do_shortcode( '[bogo]' ); ?>
</code></pre>
</li>
</ol>
<h4>Privacy notices</h4>
With the default configuration, this plugin, in itself, does not:
<ul>
<li>track users by stealth;</li>
<li>write any user personal data to the database;</li>
<li>send any data to external servers;</li>
<li>use cookies.</li>
</ul>

Bogo


There are some functionalities needed that should be in the core like change the post language, or linking to another post.



Do you have a repository to contribute?


Do you have a GitHub to contribute?

A straight-forward multilingual plugin. No more double-digit custom DB tables or hidden HTML comments that could cause you headaches later on.

Multilingual post vs Bogo