diff --git a/opensym2017/content/01-introduction.tex b/opensym2017/content/01-introduction.tex
index 13a8e30..2ea7aad 100644
--- a/opensym2017/content/01-introduction.tex
+++ b/opensym2017/content/01-introduction.tex
@@ -42,7 +42,7 @@ developed, among January 2014 and June 2016, by the University of
 Brasília (UnB) and the University of São Paulo (USP) in a partnership
 with the Brazilian Ministry of Budget, Planning, and Management (MP). It
 was designed as an integrated platform for collaborative software
-development., and includes functionality for social networking, mailing
+development, and includes functionality for social networking, mailing
 lists, version control system, and source code quality monitoring. To
 coordinate and develop this project during 30 months, UnB received from
 the Brazilian Federal Government a total of 2,619,965.00 BRL (about
diff --git a/opensym2017/content/03-requirements.tex b/opensym2017/content/03-requirements.tex
index ae56e89..caa4e7f 100644
--- a/opensym2017/content/03-requirements.tex
+++ b/opensym2017/content/03-requirements.tex
@@ -43,7 +43,7 @@ requirements were, for example:
 \end{figure}
 
 
-here were other requirements based on the experience of the IT
+There were other requirements based on the experience of the IT
 stakeholders from the Brazilian government and from the Brazilian FOSS
 community (that UnB and USP were representing too in this project). The
 new platform would only work properly if there is a unique
@@ -126,7 +126,7 @@ source code repositories are available at the Bitbucket
 platform\footnote{\url{https://bitbucket.org/softwarepublico}}.
 
 The Brazilian government needed to evolve the SPB project that
-existedince 2005. In 2013, when we started this project, the SPB Portal
+existed since 2005. In 2013, when we started this project, the SPB Portal
 had about 200 thousand registered users. We could not just contact these
 users and ask them to register an account at Github as well. Moreover,
 after the Edward Snowden case, the Brazilian government approved a
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