Setting English font size in non-English documents in XeLatex

Question

Consider a non-English document compiled in XeLatex, the standard font size is equal for all English and non-English text. How is it possible to set the size of the English text and change the font face?

Answer 1

You can use Polyglossia features: if \englishfont is defined, then XeLaTeX will use it for English text.

\documentclass{article}

\usepackage{fontspec}
\setmainfont{Linux Libertine O}
\newfontfamily{\englishfont}{Linux Biolinum O}

\usepackage{polyglossia}
\setmainlanguage{italian}
\setotherlanguage{english}

\begin{document}
Testo in italiano.

\begin{english}
Text in English.
\end{english}
\end{document}