Konnichiwa,
The first sentence in lesson 4.1 states:
"Anata wa nihon go *ga* hanase masu ka?"
However, Sayaka seems to be saying "Anata wa nihon go hanase masu ka?"
Is the 'ga' not pronounced?
Lesson 4.1

Kurisuchan
October 27, 2009

Sayaka-Matsuura
October 27, 2009
Konnichiwa Kurisuchan,
In Lesson 1.4 (I believe this is the lesson you're referring to) Sayaka's line does include the *'ga'* in *'Anata wa nihon go ga hanase masu ka?'*. Of course, in the audio, it may appear that it's not pronounced as strong as the other words, however, it is part of the sentence structure.
You may find that when you listen to native Japanese speak, they often omit some particles - but I suggest that you try not to omit particles when you are learning - so that you don't omit wrong ones, making your Japanese sound very foreign!
-Sayaka :P