Dogs are able to communicate with you, if you know what signs to look for in body language. Besides body language a dog can also communicate with their barking by changing the tone and durations of the barks.
1. Let's start off with the barks:
Continuous rapid barking at a mid range pitch
"Call the Pack", there may be a potential problem.
Barking in rapid strings with a few pauses at a med range pitch
They suspect that there may be an intruder near our territory, I think the pack leader should look into it.
Prolonged or incessant barking, with moderate to long intervals between each utterance
Is there anybody there? I am lonely and need some companionship
One or two sharp short barks at a mid range pitch
Single sharp short bark at a lower range pitch
Single sharp short bark at a higher at a higher mid range pitch
What's this? Huh? This is a strange or surprised sound. If this bark is repeated two or three times, it means "Come look at this".
Single yelp or very short high pitched bark
I'm hurting, I am really scared
Stutter bark at mid range pitch
Let's play and is used to initiate playing behavior
Rising bark, almost a yelp, though not quite that high
Used during a rough and tough tumble play time, it means, "this is fun".
Even dogs can "talk" too much. There are several options for helping control the chatter. Exercise and playtime are great to tire a dog and stimulate their minds. Understanding your dog's bark and working together to communicate can remove the strain excessive barking may have put on your relationship.
2. Next is body language:
Signs of Anxiety
These signs indicate that your dog is uncomfortable with the current situation and there is a need for intervention to prevent pushing the dog to the point of biting and to make sure your canine friend is happy.
This means that the dog wants to do something but it is suppressing the urge to do it and confusion set in. Signs of displacement behavior
Yawning when not tired
licking chops with out the presence of food or water
sudden biting or scratching it's own body parts
sudden sniffing the ground or other objects
a wet dog shake and the dog is not wet
Dogs are more overt when they feel anxious and here are some examples.
The dog gets up and leaves an uncomfortable situation (it may bite rather than leaving)
turning head away
hiding behind a person or an object
barking and retreating
a dog may roll over on it's back as a sign of submission saying "please don't hurt me"
tail between legs, ears back and rapid panting
or the dog leaves the room and urinates in another room
It is best to always have a safe place for your dog, such as a favorite blanket or a crate.
Signs of Arousal
These are signs that indicate that your dog is interested in something or trying a course of action, examples are:
ears forward, mouth closed, eyes intense
the body is rolled forward
body is tense
tail is high and tail is deliberately a slow wag
This is the type of posture we see in a dog who wants to chase a squirrel, confront an intruder. The dog is intensely focused and ready for action and does not want to be hugged or petted at this time.
There are so many signs that I have not listed in this article but wanted to touch upon some areas of communication so that you would have a better understanding of your dog.