This is not a problem if every string gets its own template for translation. If you use the string You can include a %s in a childtheme. more than one time for different nouns it is not translatable. An example, taken from a recent article: New %s is in German (yes, we have gendered nouns … Read more
__ (double underscore) is the base translate function. It translates a string and returns it as a string. _e does the same as __, but echo’s the result immediately. _x is the contextual translate function. It has a second option to provide context to people doing the translation. _ex is the same as _x, but … Read more
This is a very faceted issue. It combines inherent HTML content issues with whole new load of translation challenges, such as scanning for strings, translation process itself, and its verification. So we have to combine: Text (in translatable form) HTML markup (in hard to break, but preferably flexible form) URL destination (in secure and preferably … Read more
These are not any kind of WP’s own format but rather just gettext file types which WP implements. Translate Handbook has following definitions in its Glossary: MO files: MO, or Machine Object is a binary data file that contains object data referenced by a program. It is typically used to translate program code, and may … Read more