Yes & No! Yes, for text which can be in your language but the opening & closing HTML tags have to be in English letters.
HTML is a markup language with tags. It is used for designing interactive web pages.
To Mark up HyperText. That's what the Language was developed for.
HTML stands for Hyper Text Markup Language, HTML is not a programming language, it is a markup languageA markup language is a set of markup tags, HTML uses markup tags to describe web pages. So basically you can use it to make links on websites and even use it to make a website from scratch.
HTML is itself a language on it's own, so uses no other. Opening and closing of tags is a part of HTML.
A markup language adds codes to content that is interpreted to have specific meanings to different programs. There are many different types of markup languages. The markup language used most of the time on the Web is HTML. Hyper Text Markup Language (HTML) tells a browser how to format and display content. For example These Words tells the browser to display the characters between the tags as bold.
There are no PHP tags. Unlike HTML, PHP is not Markup language. They use scripts. An example would be <?php echo "Hello, World!"; ?>
HTML cannot work without it's tags. It uses tags for it's scripting work.
You can use Notepad to write HTML pages, and HTML consists of tags. So you would be writing a lot of tags when using Notepad to create a HTML page.
HTML is not a programming language in true sense. Though you can: write codes using HTML tags, use other scripting languages,etc to design a web page
There are a large number of tags in HTML. With each version, more ones are being added.
In definition, HTML is "Hyper Text Markup Language". This kind of language is use in a web-based application, also known as a browser ( Internet Explorer, Safari, Firefox, ..) As you said it, what is written in the HTML document, is many instructions for the browser. Those instructions can be use to: write a paragraph, draw a table, show a picture, etc... Many things can be done using HTML or XHTML ( Extensible Hyper Text Markup Language), but the use of CSS ( Cascading Style Sheet ) is needed almost for anything you want to do. Hope this solves your question.