Is it normal for search engines that every page-title of website pages
start and end with same word with only un-matching middle word?
Normal? No. Somewhat common, yes...for sites that are attempting to game the search engines. This is not a recommended action for most sites.
Also all website pages URLs can start with the same word?
I wouldn't do this. Makes your site look spammy.
Also all tags in website pages can end with the same word?
You can but I still wouldn't do this because, again, spammy behavior.
A lot of information and sites on SEO are way out of date or was never good advice to begin with. The way to good rankings in the search engines now is a combination of on-page and off-page elements of which the exact keywords on the site plays only a small factor. In fact, it is easier to hurt your SEO by gaming the keywords than it is to help yourself.
Create sites than are mobile-responsive, fast to load, and provide clear navigation combined with a good user experience. Create content that delivers your message in a clear and easy-to-consume manner, using language that is appropriate to the audience. If you do that, your issues with SEO and keywords will resolve themselves. Gaming the system will only net you a short-term benefit at best and, at worst, sets you up for severe long-term penalties.
To use your "Best Smartwatch" example in the comments above, it is perfectly natural to have a page on your site titled:
"Which is the best smartwatch on the market today?"
and to also have an opening sentence like:
"There has been an explosion of smartwatches in the last year with
devices running Android, iOS and other operating systems. But which is
the best smartwatch today?"
and then go from there. Same sort of concluding sentence and one assumes the phrase "best smartwatch" appears in the content naturally and normally. This type of keyword use is considered good SEO.
On the other hand, consider a page with the title:
"Best Smartwatch from Best SmartWatch dot Com: Best Smartwatches"
and an opening sentence of:
"Best Smartwatches are the best smartwatch that users of smartwatch
like best and best smartwatch can be iOS or Android or Fitbit and are
the best smartwatch to use for email, text message or fitness tracking
because they are best smartwatch"
Aside from being both a grammatical and syntactical disaster which will raise your bounce rate, the above will more than likely get you flagged as a spammer. Make sense?