Can someone help me with this? I am really new to Latex and this really frustrates me
\documentclass[12pt]{article}
\usepackage[top=2.54cm, bottom=2.54cm, left=1.91cm, right=1.91cm]{geometry}
\usepackage[english,greek]{babel}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{textgreek}
\babeltags{en = english}
\begin{document}
\title{Δισκόμορφοι Υγροί Κρύσταλλοι}
\author{Θεοδωρίδης Αθανάσιος}
\maketitle
\section*{1. Εισαγωγή}
Η μελέτη των υγρών κρυστάλλων ξεκίνησε το 1888 από τον βοτανολόγο \en{Friedrich Reinitzer} , ο οποίος εξέταζε τις ιδιότητες διαφόρων παραγώγων χοληστερίνης, και παρατήρησε την αλλαγή των ιδιοτήτων τους με την μεταβολή της θερμοκρασίας.
\end{document}

\usepackage[LGR,T1]{fontenc}help? Please include your code as copy-and-paste-able text in your question. An image is not searchable for text and we don't have to re-type its contents. – moewe May 11 '18 at 13:43\enseems to be a switch and not a macro. Try{\en Friedrich Reinitzer}and not\en{Friedrich Reinitzer}. Edit according to thebabeldocumentation\texten{Friedrich Reinitzer}(withtext) is preferred. – moewe May 11 '18 at 13:48\begin{en}...\end{en}for two words. – moewe May 11 '18 at 13:51\usepackage{textgreek}if you type Greek directly and don't use\textalphaetc. – moewe May 11 '18 at 13:59\section{Εισαγωγή}instead of\section*{1. Εισαγωγή}. That way TeX does the counting and numbering of the sections for you. If you want the dot back, have a look at https://tex.stackexchange.com/q/24439/35864 – moewe May 11 '18 at 14:28