---is a spacer. Like "in fact". "essentially" "well", or dozens of other variations, they are nonsense words added at the front of a sentence, mostly to give the speaker time to think of what to say next, or in written text, to make the sentence more euphonious and rhythmic. They are a pause, or a prefix to warn the listener something follows. Everybody uses them, myself included, especially in spoken speech, but some people abuse them.

A similar construction is the Canadian, "eh?", added after a sentence as if prompting the listener for approval. American English speakers also use a particularly annoying verbal gesture, the pause, usually marked by a really dufus-sounding "...uh..." inserted in a sentence while the speaker collects his thoughts and figures out what he's going to say next.

"I was going to the ...uh...store and...uh...my car wouldn't start. I tried calling the...uh...garage, but all I got was one of those...uh...recorded messages."

You may not have noticed yourself doing this, but it is a common feature of American English--so common we don't realize we're doing it. Myybe I notice it because my machine-gun Cuban Spanish barely slows down enough to let me catch my breath. It's not that American English speakers are particularly inarticulate or illiterate, its just a bad habit many of them have picked up along the line and it has not been drilled out of them in school. Brits don't do it, nor do other English speaking countries. I don't do it, which has led some people to accuse me of talking too fast, or too "fancy". I don't mind, I am a fucking elitist, and proud of it.

"...uh..." drives other people crazy, and most Americans don't even realize they are doing it, unless they've had formal speech training. But it makes us (American English Speakers) sound really dumb. It is especially noticeable when people are speaking extemporaneously in public, not so much when talking amongst friends or family.

Yes, I do often pause myself to search for the right word, when speaking English or Spanish, to think over what I'm going to say, or to try and think ahead and phrase my thoughts appropriately, but I just pause, or even change inflection slightly to distract the listener from my pause. But I don't add the "...uh..." sound. My grandfather found this really annoying, because even politicians or educated speakers punctuated their radio and TV broadcast sentences with "...uh...". It use to drive him nuts, and he barely spoke English at all (although he could understand, read and write it perfectly).