Spotlight has expanded its reach with OS X El Capitan and has a greater ability to understand you, both welcome developments. The search agent for OS X now pulls in results for weather, sports and stock information, and it can also perform Web searches for Vimeo and YouTube videos. In addition, it lets you use natural language to find what it is you are looking for.
In my short experience with El Capitan thus far, the expanded Spotlight has suffered from growing pains. While I was able to use the new weather and sports functions, Spotlight failed to understand my queries for stock prices. I simply needed to type "weather" and Spotlight showed me current conditions, the hourly forecast and 10-day forecast a la the stock weather app in iOS. I could also ask for the weather in a different city.
For sports, I was able to use Spotlight to check in on the sorry state of my Cincinnati Reds. Searching for "Reds roster" let me scan the team's current roster for potential trade chips as we approach the trading deadline, and "Reds standings" let me see that they are well behind the pace in the NL Central.
I was also able to use natural language queries, but this newly added ability seems to work only for local results. While the query "Reds score from Sunday" failed to turn up any results, the simple search "Reds scores" showed me their their last five results and the next five games on the schedule.
For local searches, I could ask Spotlight for "photos from yesterday" and browse the photos I snapped and imported to the Photos app yesterday. Or I could search for "emails from Monday" to see the emails in the Mail app I received that day. I had less luck searching for emails from particular contacts; Spotlight shows results for emails from years ago when much more recent correspondence was available.
For Vimeo and YouTube searches, I found I needed to get as close to the actual title of the video and add the term "vimeo" or "youtube" to my query to be successful.
Lastly, Spotlight is no longer a fixed box. You can drag the bottom of the window to make the Spotlight window longer to see more results with less scrolling needed, but you can't stretch Spotlight to widen it.