i.e., it takes any sentence/phrase as input and automatically figures out the tree diagram.
I'm looking for a way to see the tree structures for sentences/phrases whose tree structures I'm unsure of how to draw.
This question is related to
linguistics
In short, yes. I assume you're looking to parse English: for that you can use the Link Parser from Carnegie Mellon.
It is important to remember that there are many theories of syntax, that can give completely different-looking phrase structure trees; further, the trees are different for each language, and tools may not exist for those languages.
As a note for the future: if you need a sentence parsed out and tag it as linguistics (and syntax or whatnot, if that's available), someone can probably parse it out for you and guide you through it.
There are lots of options out there. Many of which are available as downloadable software as well as public websites. I do not think many of them expect to be used as API's unless they explicitly state that.
The one that I found effective was Enju which did not have the character limit that the Marc's Carnagie Mellon link had. Marc also mentioned a VISL scanner in comments, but that requires java in the browser, which is a non-starter for me.
Note that recently, Google has offered a new NLP Machine Learning API that providers amoung other features, a automatic sentence parser. I will likely not update this answer again, especially since the question is closed, but I suspect that the other big ML cloud stacks will soon support the same.
Source: Stackoverflow.com