Martin Lormes

Change the quotation marks, that are automatically rendered as smart or curly quotes inside your content, from the default English style (“…”) to anything you like, e.g. to Croatian/Hungarian/Polish/Romanian style quotation marks („…”), Czech or German style („…“), Danish style (»…«), Finnish or Swedish style (”…”), French style (« … » – with spaces), Greek/Italian/Norwegian/Portuguese/Russian/Spanish/Swiss style («…» – without spaces), Japanese or Traditional Chinese style (「⋯」), or actually to any arbitrary character combination of your choice. Of course you can turn off curly quotes entirely by picking the so-called "dumb" quotes ("…").

Smart Quotes

Change the quotation marks that are automatically rendered as smart or curly quotes inside your content.

Scott Reilly

By default, WordPress converts single and double quotation marks into their curly alternatives. This plugin prevents that from happening, so you can enjoy your quotation marks in their non-curly glory. If your content happens to already have curly quotation marks in it, then this plugin can optionally also convert them to their non-curly alternatives.
Note: Despite the unfortunately misleading name, this plugin is NOT the antithesis of WordPress’s <code>wptexturize()</code> function. This ONLY prevents WordPress from making HTML entity code substitutions of single and double quotation marks with their curly alternatives and does NOT prevent <code>wptexturize()</code> from making any other character and string substitutions. See the FAQ for details on the filters processed by the plugin.
Links: <a href="https://coffee2code.com/wp-plugins/wpuntexturize/" rel="nofollow ugc">Plugin Homepage</a> | <a href="https://wordpress.org/plugins/wpuntexturize/" rel="ugc">Plugin Directory Page</a> | <a href="https://github.com/coffee2code/wpuntexturize/" rel="nofollow ugc">GitHub</a> | <a href="https://coffee2code.com" rel="nofollow ugc">Author Homepage</a>
<h3>Developer Documentation</h3>
Developer documentation can be found in <a href="https://github.com/coffee2code/wpuntexturize/blob/master/DEVELOPER-DOCS.md" rel="nofollow ugc">DEVELOPER-DOCS.md</a>. That documentation covers the numerous hooks provided by the plugin. Those hooks are listed below to provide an overview of what’s available.
<ul>
<li><code>c2c_wpuntexturize</code> : An alternative approach to safely invoke <code>c2c_wpuntexturize()</code> in such a way that if the plugin were deactivated or deleted, then your calls to the function won’t cause errors in your site. This only applies if you use the function directly, which is not typical usage for most users.</li>
<li><code>wpuntexturize_filters</code> : customize what filters to hook to be filtered with wpuntexturize. See the Description section for a complete list of all filters that are filtered by default.</li>
<li><code>c2c_wpuntexturize_replacements</code> : Customize the character replacements handled by the plugin.</li>
<li><code>c2c_wpuntexturize_convert_curly_quotes</code> : Enable conversion of preexisting curly quotes into their non-curly alternatives.</li>
</ul>

wpuntexturize

Prevent WordPress from converting single and double quotation marks into their curly alternatives.

Smart Quotes vs wpuntexturize