How can I tell if my finished basement is leaking?

Question:I just bought a house and noticed that the garage walls are leaking. I have a finished basement with drywalling and carpeting. Is there any way I can check to make sure it is not leaking there too? The basement and garage are on the same level. My neighbor told me he remembers the previous owner having leaking problems in both rooms. But nobody lived there 6 months before I moved in so I thought I would have smelled it or noticed water on the rug. Also, another neighbor said 6-7 years ago the back of the house was dug up to the foundation and sealed with gravel and french drains. Should I check the french drain doesn't leak?

Answers:
You can check for water in the drywall or carpet using a moisture tester like this:
http://www.amazon.com/sonin-50211-rapite...