# How to use “&” in a “spanish-english” document

I am writing my thesis in Spanish, but i have 2 chapters in English. What I need is:

Use "&" in all references in both languages.

My problem is that all my chapters (English and Spanish) are using "y" instead of "&"

I'm using biblatex:

\documentclass[11pt, spanish, singlespacing, headsepline,]{PhDDoctoralThesis}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{palatino}
\usepackage[maxbibnames=99,backend=bibtex,style=authoryear,natbib=true]{biblatex} %
\DefineBibliographyStrings{spanish}{%
}


NOTE: In myfile.cls appears \RequirePackage{babel} but I'm not using \usepackage{babel} in my main.text

NOTE2: I wrote my English chapters by using \renewcommand{\chaptername}{Chapter}.

• You also appear to be using babel. Is this hunch correct? – Mico Nov 17 '17 at 21:31
• What about all other localisation strings in biblatex? Do they need to be English or Spanish? (Assume it matters even if in practice the strings coincide). It would help to see an MWE/MWEB. Because we need to know how you set up your language stuff (babel) and how you change the language in the two English chapters. – moewe Nov 17 '17 at 23:50
• I've updated my post with more information. Thank you! – Juan Espinosa Nov 18 '17 at 0:04
• You mention myfile.cls but you load PhDDoctoralThesis.cls. There are many versions of that template around. Which do you use exactly? – moewe Nov 18 '17 at 0:09
• Version 1.5 2016/11/22 latextemplate.com – Juan Espinosa Nov 18 '17 at 0:12

\DeclareDeliFormat{finalnamedelim}{\addspace\&\space}

will make the delimiter between the last two names an &. But because Spanish is special with 'y' and 'e' you will also need to reset \lbx@finalnamedelim with
\makeatletter

This is an answer for biblatex v3.8 and above. See the edit history for an answer for older versions.