TeXworks: How to add a word to the spell checker dictionary?

TeXworks uses a spell checker called Hunspell, an engine which is also used e.g. by OpenOffice:

Each dictionary consists of two files with the extensions .dic and .aff. Where these are located depends on your TeXworks installation, on my system (TeX Live 2010, Windows), they are in the directory

C:\Users\<user name>\.texlive2010\texmf-config\texworks\dictionaries

Adding words to the dictionary is quite simple: As the .dic file is a plain word list, you can just add new lines with your own words. If you want the system to recognize different word forms, too, you have to deal with the .aff file - see this explanation for more details. However, simply changing the word list should be enough in most cases.

I managed to install the dictionary PT_EU as follows:

I opened the TeX works went to Help -> Settings and Features and clicked C:/Users/Abilio/AppData/Local/MiKTeX/2.9/TeXworks/0.4

After downloading the dictionary did PT_EU http://extensions.services.openoffice.org/en/dictionaries site, downloading a file. Otx. then open this file with 7-zip, and copied the folder "Dictionaries" folder to the 0.4.

Then I copied the entire folder TeXworks (C:/Users/Abilio/AppData/Local/MiKTeX/2.9/TeXworks/), to the following path C:/Users/ Abilio / AppData / Local /. Then I reopen the TeXworks, and the dictionary was already there and it worked.

I have windows Vista 32-bit.

In a MiKTeX 2.9 / Windows 8 context, the file to modify turned out to be

/Users/(username)/AppData/Local/Programs/MiKTeX 2.9/hunspell/dicts/en_US.dic

There was no problem editing it with a Unix-style editor within Cygwin. The file has a word count at the beginning, but it did not seem necessary to increment the word count when adding new words. I presume the word count is used for storage allocation when the file is loaded. I added new words in alphabetical order.

The remark above about making a backup is right on!