# Kerning issue between the letters “f” and “i” [duplicate]

I noticed that after compiling a document using TeXWorks and PDFLaTeX (I made a clean install less than a month ago) there seems to be a strange kerning issue whenever "f" and "i" appear next to each other in textmode and I have no idea what is causing it. If I compile the text and try to highlight it in a pdf reader, it seems to treat "fi" as its own character and I cannot highlight just the "f" or the "i". In all other cases the kerning seems fine.

\documentclass[11pt]{amsart}
\usepackage{graphicx}
\usepackage{epstopdf}
\usepackage{amsthm}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{amsxtra}
\usepackage{amscd}
\usepackage{verbatim}
\usepackage{rotating}
\usepackage{multirow}
\usepackage{multicol}
\usepackage{url}
\usepackage[all]{xy}

\begin{document}
identities for modified lattice paths by establishing a bijection
\end{document}


• That’s called a ligature, and it’s meant to avoid awkward collisions of letters. Now that you know what it’s called, you’ll find many questions about ligatures on this site. – Thérèse Jan 27 '18 at 2:50
• @Thérèse Thank you I think I found all the information I need now that I know the correct terminology. I am unsure if I should delete this question now. – Echan Jan 27 '18 at 3:42