# How can I write a non-greek name in a greek text?

I want to write a text in Greek and there are some non-greek names.

I used the following code:

\begin{frame}{Ιστορική αναδρομή}
Το 1926 ο $\textenglish{David Hilbert }$ ισχυρίζεται ότι κάθε υπολογίσιμη συνάρτηση είναι πρωταρχικά αναδρομική.  $\\ \\$
\end{frame}


I used the following package:

\usepackage[english,greek]{babel}


But I get the following error:

Undefined control sequence.
\beamer@doifinframe ...-Το 1926 ο \textenglish
{David Hilbert } ισχυ�...
l.66 \end{frame}

The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., \hobx'), type I' and the correct
spelling (e.g., I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.


What have I done wrong?? What could I change??

• First question, why math mode? – Johannes_B Apr 13 '15 at 10:43
• Do you mean why I use the  ?? I tried it without them, and since it didn't work I tried it with them but it still doesn't work... @Johannes_B – Mary Star Apr 13 '15 at 10:46
• \foreignlanguage{english}{David Hilbert} . And all this math is simply wrong. – Ulrike Fischer Apr 13 '15 at 10:47
• When I write this instead of \textenglish{} I get exactly the same erroe as before, although I don't use \textenglish{} it says that "Το 1926 ο \textenglish {David Hilbert } ισχυ�... l.66 \end{frame}" Why?? @UlrikeFischer – Mary Star Apr 13 '15 at 10:55
• LaTeX doesn't invent commands. If is says there is a \textenglish, it is there. So check if you saved the file, changed the right file, changed all occurances of \textenglish, etc. – Ulrike Fischer Apr 13 '15 at 10:59

Use \foreignlanguage{english}{David Hilbert}`.