The default template explanation here

- news_single.tmpl, news_list.tmpl and relation with tt_news and news_template.tmpl -

Two files can be use adjust the specific of your laguage environment.

The file from sg_newsplus  called locallang_db.php located in your sg_newsplus extension folder (normally: ./typo3conf/ext/sg_newsplus/locallang_db.php) and the file locallang.php from the sg_zfelib extension located in the installation folder (normally ./typo3conf/ext/sg_zfelib/locallang.php).