When I use Dictation Commands in Yosemite,such as 'select all', it types it as text.

Anna Kist,

I would first check to see that the commands your trying are enabled or checked in System Preferences. To do so go to:

System Preferences > Accessibility > Select "Dictation" on the left > Click the ( Dictation Commands ) Button > Make sure what your trying to use is checked.

Hope that helps,

Weston

Supporting Articles,

Mac Basics: Dictation lets you speak text instead of typing

Dictation commands you can use in OS X

OS X Yosemite: Use Dictation Commands to tell your Mac what to do

Anna,

”Select All,” is not a legitimate Dictation keyword. Here is the list of reserved words, and no, it doesn't get all of these correctly either. Dictation is a learning software, and the more you use it, the better it will adapt to your voice patterns.

Anna,

I read somewhere that its a good idea to also check your input volume and make sure it is set to a comfortable level. Go To:

System Preferences > Sound > Input ( Tab ) > make sure "Input level:" stays near the middle when you talk. If its to low or to high adjust "Input Volume"

Also read that it may help if the cache is cleared out. To do so go to:

System Preferences > Dictation & Speech > Dictation ( Tab ) > Temporarily turn off Dictation:

After delete the cache file folder:

Macintosh HD > Users > Your User > Library ( Hidden Folder ) > Caches > "com.apple.SpeechRecognitionCore" (Folder)

**Helpful Tip** While in finder press and hold the ( Option ) Key and select Go > Library from the menu. It will take you to your users library folder.

Now Turn back on Dictation:

System Preferences > Dictation & Speech > Dictation ( Tab ) > Turn on Dictation:

Hope that helps,

Weston

Supporting Article,

http://www.cnet.com/news/troubleshooting-enhanced-dictation-in-os-x-mavericks/