Keyword / phrase online

I do not believe any such list exists. I also am not aware of any tool that automatically shows only specified words - especially at the beginning - and excludes all other related search phrases.

I could be wrong, but I've never heard of such a thing.

I'm sure there is a way to do it by exporting a list from KeyWord Planner and then filtering those results with Excel. You CAN set the Keyword Planner tool for a specific time period, such as the last 30 days. You can also change the filter to show "closely related ideas" instead of the default "broadly related ideas" which usually kicks out most of the results without the specific words in it (but they will not just be at the beginning of the search phrase).

I have also a website and i also looking for keyword researching tool. But as you says there is not a single tool which shows you list.

According to me Human mind is better than any tool. Believe me if you can google the words and go with similar keywords or you can use Keyword Planner for free.

You must be joking to ask for a goldmine and that too for free.

It doesn't exist & never will, it's a thing that you need to find by yourself.

You might not be able to get exactly what you're looking for - but you can get close and get a list that's useful:

Go to Ubersuggest: https://neilpatel.com/ubersuggest/

Type in your keywords eg Dog Training and hit search.

On the left hand side of the screen you'll get a big list of keyword ideas that start with your keywords.
You can use the filters to include or exclude other keywords and refine your list.

It's not perfect - but it's pretty good for free.

You could also create a list of Google's suggestions (which come from other people's searches) manually:

Go to Google, type in your keywords (eg Dog Training) then type A.

Google will return a list of suggestions that start with Dog Training, where the next word starts with A.
eg.
Dog Training Aids
Dog Training Accessories
etc

Note these down and move on to B

You can even go to the next level:
When Google suggests Dog Training Aids - type that in, and it will suggest

Dog Training Aids to Stop Barking
Dog Training Aids to Stop Pulling
etc

I think only Google has that data. The public can't access it.

While it would not be the EXACT numbers, you can get directional information on search volume and inventory from the Google Adwords Keyword Planner Tool.

https://ads.google.com/home/tools/keyword-planner/

It will allow you to enter a single keyword or a group of keywords relevant to your site and you will get the search volumes Google chooses to share along with competition and relevance.

Another tool that gives directional insight is Google Trends.

https://trends.google.com/trends/

This tool will give directional insight into several keywords for comparison.

These are the best basic free tools I know for this type of analysis, other options are available but for a fee.

Google is privy to that type of data. And I believe it is part of his business secretes. If you can get a software to get you that then google will be done.

Go to Google Trends, enter in your search term/word, select 12 month period, and it will bring in a list of results of the trending keywords (what people have been searching for - related to your search term). I think that's exactly what you're looking for.