\documentclass[a4paper,10pt]{article}

\usepackage[italian]{babel}
\usepackage[utf8x]{inputenc}
%\usepackage[latin1]{inputenc}

\usepackage{lipsum} 

\begin{document}


\lipsum[1]

\begin{center}
testo centrato
\end{center}

\lipsum[1]

\centering
testo centrato

\lipsum[1]









\end{document}