Fix the english.

doc/development/ui_guide.md

@@ -14,28 +14,23 @@ repository and maintained by GitLab UX designers.
 
 ## Navigation
 
-GitLab layout contains of 2 sections: left sidebar and content. Left sidebar 
-contains static navigation menu no matter what page you visit. It also has GitLab logo 
-and current user profile picture. Content section contains of header and content itself.  
-Header describes what area of GitLab user see right now and what navigation is 
-available to user in this area. Depends on area (project, group, profile setting) 
-header name and navigation will change. For example when user visits one of the 
-project pages the header will contain a project name and navigation for project 
-pages. When visit group page it will contain a group name and navigation related 
-to this group.
+GitLab's layout contains 2 sections: the left sidebar and the content. The left sidebar contains a static navigation menu. 
+This menu will be visible regardless of what page you visit. The left sidebar also contains the GitLab logo 
+and the current user's profile picture. The content section contains a header and the content itself.  
+The header describes the current GitLab page and what navigation is 
+available to user in this area. Depending on the area (project, group, profile setting) the header name and navigation may change. For example when user visits one of the 
+project pages the header will contain a project name and navigation for that project. When the user visits a group page it will contain a group name and navigation related to this group.
 
 ### Adding new tab to header navigation
 
-We try to keep amount of tabs in header navigation between 5 and 10 so it fits on 
-a laptop screens and doest not confure user with too many options. Ideally each 
-tab should represent some separate functionality. So everything related to issue 
-tracker should be under 'Issues' tab while everything related to wiki should 
-be under 'Wiki' tab etc.
+We try to keep the amount of tabs in the header navigation between 5 and 10 so that it fits on a typical laptop screen. We also try not to confuse the user with too many options. Ideally each 
+tab should represent separate functionality. Everything related to the issue 
+tracker should be under the 'Issues' tab while everything related to the wiki should 
+be under 'Wiki' tab and so on and so forth.
 
 ## Mobile screen size 
 
-We want GitLab work on small mobile screens too. Because of size limitations 
-its impossible to fit everything on phone screen. Its ok in this case to hide 
-part of the UI on smaller resolutions in favor of better user experience. 
-However core functionality like browsing file, creating issue, comment, etc should
+We want GitLab to work well on small mobile screens as well. Size limitations make it is impossible to fit everything on a mobile screen. In this case it is OK to hide 
+part of the UI for smaller resolutions in favor of a better user experience. 
+However core functionality like browsing files, creating issues, writing comments, should
 be available on all resolutions.
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