\documentclass{article}

\usepackage[margin=1in]{geometry}% Just for this example
\usepackage{paracol,lipsum}

\begin{document}

\sloppy% Just for this example
\lipsum[1]

\columnratio{0.4}
\setlength{\columnseprule}{.4pt}
\begin{paracol}{2}
  \small

  \lipsum[2]

  \switchcolumn

  \lipsum[2]

  \switchcolumn*

  \noindent{\normalsize\bfseries 4 \quad Some section}

  \noindent\lipsum[3]

  \switchcolumn

  \noindent{\normalsize\bfseries 4 \quad Some section translated}

  \noindent\lipsum[3]
\end{paracol}

\lipsum[4]

\end{document}