It does have some kind of spelling correction. Searching for 'spellings' and sorting on newest gives your question as one of the top results, even though it does not contain the word 'spellings':
This is the result of using so-called stemmers in Elasticsearch, the repository powering the Stack Exchange search.
If you frequently misspell words, it's better ...
It's possible (sort of) with a SEDE query, if you don't mind the results will be up-to-date up to last Sunday. Given that you're often searching for questions you bookmarked long ago, this shouldn't be much of a problem.
The query needs your network account ID, which is the number that appears in the address bar if you navigate to https://stackexchange.com/...
You're getting results for all posts, not only questions. The first post in your search results is of an answer, that's what the "A:" prefix means. The second result is a question, indicated by the "Q:".
If you would like questions only, then add is:q to your search and you will not see answers.
To be clear it's not showing the questions twice - it's actually showing you the question and then the answers to the question (if there are any). Search returns both questions and answers.
If you want to only include questions in your results, then you can include a filter of is:question. You can see the Advanced Search options by clicking Advanced Search ...
Something's wrong with whatever parses the search string, when you add the is:a bit. Note the response:
We couldn't find anything for दव सपरण
It has actually split out the combined characters into separate ones.
If I search for "द्वा सुपर्णा" is:a, it works correctly.
This already exists as an advanced search operator; e.g. searching for created:1d.. gives all posts from the last 24 hours.
You can use specific dates or date ranges to narrow results down to posts created or active within a certain time period, using the following operators:
created: to specify when the posts were created
lastactive: for posts ...
All current answers here missed the simple and honest mistake made: using a comma.
In order to show questions having two tags, just have a space between them, no comma:
This way you'll get only the questions, no answers, in the search results.
By adding a comma (or anything else) you turn this into ordinary search, which returns both questions and answers, ...