Dear Aditya,

context([[\def\noexpand\Lang{...}]])

not working

or

context([[\def\string\Lang{...}]])

working

I don't understand why

context([[\def\\Lang{...}]])

working, too You are right. [[\def\\Lang{English}]] method works. I summerize it as a test file. The first 5 methods are working well, but the last one using \noexpand cause the error. Thank you. Best regards, Dalyoung \mainlanguage[en] \starttext \startitemize[n] \head Using \type{context.setvalue("Lang","English")} \startluacode if languages.current() == "en" then context.setvalue("Lang","English") else context.setvalue("Lang","Not English") end \stopluacode Current language: \Lang \head Using \type{context("\\def\\Lang{English}")} \startluacode if languages.current() == "en" then context("\\def\\Lang{English}") else context("\\def\\Lang{Not English}") end \stopluacode Current language: \Lang \head Using \type{context([[\def\string\Lang{English}]])} \startluacode if languages.current() == "en" then context([[\def\string\Lang{English}]]) else context([[\def\string\Lang{Not English}]]) end \stopluacode Current language: \Lang \head Using \type{context([[\def\\Lang{English}]])} \startluacode if languages.current() == "en" then context([[\def\\Lang{English}]]) else context([[\def\\Lang{Not English}]]) end \stopluacode Current language: \Lang \head Using \type{\doifelse\currentmainlanguage{en}...} \doifelse\currentmainlanguage{en} {\def\Lang{English}}{\def\Lang{Not English}} Current language: \Lang \head Using \type{context([[\def\noexpand\Lang{English}]])} %\startluacode % if languages.current() == "en" then % context([[\def\noexpand\Lang{English}]]) % else % context([[\def\noexpand\Lang{Not English}]]) % end %\stopluacode %Current language: \Lang \stopitemize \stoptext