I'm learning languages and in my opinion, one way to improve my skills is to read books aloud. Making it a habit would help me with my vocabulary, pronunciation, grammar, etc.
I also think there might be some people online who would be interested in listening to books that I read aloud.
Therefore, I wonder, can I read parts of a book aloud online? Could I publish these videos on YouTube? Is that legal? I don't mind reading from older books, as I read those books might be public domain
The following answer is based on US-law. I am not a lawyer; this is not legal advice.
If the book you read is in the public domain* you should be fine. Otherwise what you are doing is copyright infringement and probably not protected by fair use**.
One of the rights granted to copyright holders is to control derivative works, and transference to different mediums, which is what your recordings would be.
Under US law, whether an instance of copyright infringement is fair use is evaluated on a case-by-case basis, weighing four points:
the purpose and character of one's use
the nature of the copyrighted work
what amount and proportion of the whole work was taken
the effect of the use upon the potential market for, or value of the copyrighted work
In my non-lawyer evaluation, point 1 depends on what you do in your video (unless you monetize your Youtube video, in which case it is likely to be decided against you), but if you are merely reading the book out aloud, it is unlikely to be in your favor (although it may not be against you as an "educational tool").
Point 2 depends on what is being read, with a informative work (e.g. a textbook) being more likely to be fair use than a creative work (e.g. a novel).
Point 3 depends on how much and what proportion of a work you use; since you are presumably reading a whole book, this would most likely be ruled against you.
Point 4 would almost certainly be decided against you, as you are essentially creating an unauthorized audiobook.
In summary, you can read a book aloud. You can record your reading of it for your personal use. You should NOT upload it to Youtube, or other sharing sites.
*Note that different countries have differing rules on when a book enters the public domain, and since the internet crosses borders, multiple rule sets may apply.
If the work is in the public domain (probably through the copyright having expired) there is no copyright protection, so the issue of fair use does not arise.
Fair Use is an exception to copyright in US law. In the copyright laws of other countries than the US there are various exceptions provided, but they not are very close to fair use in scope. Copyright infringement suits can be brought in any country where infringement takes place. The local copyright law applies in such cases.
There are not enough specific facts provided to make a reliable fair use analysis, much less consider any of the various non-US exceptions to copyright.
If the apparent purpose is educational, that tends to tilt toward fair use for factor 1. Just how much of the book would be read aloud would need to be known to make even an approximate judgement on factor 3, and that might also affect factor 4, particularly on whether the video could serve as a replacement for the original.
In some counties there are specific exceptions to copyright for "personal use" but not in US law to the best of my knowledge.
