Question about verb forms

[法月]

Hi,

I've been reading a few things in Japanese, and there's one thing I can't quite figure out.
For example:

分かってる and 分かっている
読んでる and 読んでいる
信じてる and 信じている

To me, the pairs mean [I] understand, [am] reading, and [am] believing, respectively---I don't understand the distinction between the two words in each pair. I'd really appreciate it if someone would elaborate on the differences between the two in each.

Thank you in advance,
法月

[Harv]

In informal Japanese the い in いる is often omitted.

[法月]

Thanks for the response, Harv. Not doubting you or anything, but can anyone else confirm this as well?

[Tom]

He speaks the truth!

[法月]

Thanks for the information and confirmation