# Hyphenation command doesn't print

I am having problems during the writing of my thesis. Everytime I use \hyphenation to split a ward so that it goes on a new line rather than going out of the margins, that words disappear instead.

An example is:

In addition, mechanistically more challenging transformations have
\hyphenation{be-en} extensively studied in recent years, including
NHC-catalyzed transformation


As you can see, the "been" is missing.

I have nothing specified in the preamble.

• How are you using \hyphenation? Are you aware that it is meant to be used in the preamble to tell TeX where it is allowed to hyphenate certain words with which it needs help? – cgnieder May 29 '17 at 10:20
• No, I did not know. – Giovanni Di Mauro May 29 '17 at 10:22
• Please edit the question to provide a Minimum (non)Working Example of your problem. Just giving us a long list of packages (most of which are probably irrelevant to the problem) and saying "I did something, but it doesn't work" is not very useful. – alephzero May 29 '17 at 10:22
• as noted above \hyphenation is being misused here but also the default rules for english do not break been as be-en with good reason, the break there would be so bad as to render it almost unreadable, surely you can break somewere else even if it causes some space to stretch. – David Carlisle May 29 '17 at 10:42
• Hyphenating be-en is utterly wrong, I'm afraid. It would be like hyphenating pi-anura in Italian: a diphthong is never split. – egreg May 29 '17 at 10:49

\hyphenation is a declaration to be used in the preamble that declares how automatic hyphenation should work on a particular word so

\hyphenation{trans-for-ma-tions}


for example would specify the places TeX could break transformations (this is actually the default in this case).

For one-off discretionary hyphen within the body of the document you can use \- but it would be very wrong to hyphenate been.

You hadn't provided a real example but I assume that your case is like this with an overfull box:

Overfull \hbox (2.73953pt too wide) in paragraph at lines 8--11
[]\OT1/cmr/m/n/10 In ad-di-tion, mech-a-nis-ti-cally more chal-leng-ing trans-f
or-ma-tions have been


From the input

\documentclass[a4paper]{article}

\begin{document}

Zzzzzz\dotfill zzzz

In addition, mechanistically more challenging transformations have
been extensively studied in recent years, including
NHC-catalyzed transformation

Zzzzzz\dotfill zzzz
\end{document}


Changing been to be\-en would remove the warning at the cost of making the text much harder to read. There are much better alternatives, for example if you add

\usepackage{microtype}


then not only does the overfull box go, so does the slightly ugly short final line of the paragraph with just the tion from the end of transformation

\documentclass[a4paper]{article}