When, for your dining enjoyment, a child hands you a sandwich made of Legos, it’s a superb idea to ask her what every single Lego block is. You’d better remember which is the patty, the Volcano Sauce, the Sea Horseradish, the multiple mustards, and the Jellyfish Jelly. Woe unto you if you assume any one of those Legos isn’t important. Or is not there for a specific and incredibly useful reason. Each Lego in that foot tall sandwich has a function or it absolutely would not be there.
The same is true for a small child’s drawing. What looks like aimlessly scribbled scrawls of pencil lines and infinitesimal dots… to you… has essential and well-thought-out meaning for the artist. Nothing is there without an objective. Their creator can damn well tell you the reason for every hen scratch. Just ’cause it looks like gobbledygook gooey goo to you doesn’t mean it is. All has meaning. Each line adds to the work’s overall goal.
With writing, the opposite is true. Material often clouds the page solely because the writer can type fast.
If we wrote with quill pens we repeatedly dipped in ink, this pernicious word-vomitorium would be less of a thing. As the quill has gone the way of the Dodo, we tend to make our readers suffer.
When constructing a sentence, writers are WAY less diligent than children making art. Grownups are sloppy. When someone writes with next to no deliberation, sentences can have heaps of greasy fat, settling hard on the tum-tum unwanted and unappreciated. A paragraph can contain wasted words, useless phrases, or (gasp!) entire sentences that have no cause for existence.
If you don’t have one caroming around the house, either rent a kid to proofread your work and tear out every single word you don’t need… like getting rid of extra lettuce in a Lego sandwich… OR make the perhaps unfamiliar effort to proofread and rewrite exactingly all by yourself.
When it’s over, be certain nothing is on your page without a raison d’être. Just ’cause it’s there doesn’t mean you gotta keep it, unlike the six Lego mustards.
Your Screenplay Sucks! 
I was a judge for a major contest and after one year of wading through 160 or so manuscripts came up with the most common reasons I put something down after five pages. Having recently returned from Scotland, I call it the BEST CURRVE. B: Boring. I used to think that was due to lack of conflict, but have since decided it is lack of change. Two old guys in the bar can have the same argument every Friday night over who was the best boxer… and conflict without change becomes tiresome. If there’s no change, why is it there? E: Extra words, which you mention here. I also look for filler words like, “just, still, now, start”, and my worst enemy, “that.” S: Senses. Think of your senses like a bag of golf clubs. Try to use more than visual whenever you can. T: Telling, not showing. Duh! C: Confusing. “Jane and Sally had lunch when her boyfriend called.” You want the reader curious, not confused. U: Unbelievable. R: Repetitious. R: Reveal: Telling me too much too soon. V: Vary the sentence length. E: Ending. The last word in a sentence, the last sentence in a paragraph, and the final sentence in your work, are the most powerful. Think of a gymnast doing a floor routine and “stick’ the landing, for that’s what will linger with the reader when they’re done.
My two farthings.