By default, in an inline equation, the indices of a sum are placed besides the sum.
This can be changed by using the \limit command!
$\sum\limits_N$
Babel packet:
Supports multiple languages in a latex document.
\usepackage[ngerman,english]
Uses english as default language and the new german grammar as secondary language.
Use \selectlanguage{language} to switch between languages.
Commands can distinguish between languages using
\iflanguage{ngerman}{Zitiert auf}{cited on}