Looking on the internet deeply has found these results:

they never fail me is the most popular phrase on the web.

they never fails me 112,500 results on the web	they never fail me 129,700 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
And yet, they never fail to remind me that I can do no right. And they never fail to have some nimble talent. Never fails, my dear sir, it never fails. With this machine, the splendor of world should never fail. Or you promise me that you will never fail me again in any capacity, and we can all go on back about our evening. They are so opportunistic that they never fail to profit from the knowledge accumulated by men through the ages. I Knew My Oldest Friend Would Never Fail Me. A mother's instinct never fails.	And they never fail to have some nimble talent. With this machine, the splendor of world should never fail. A mother's instinct never fails. Never fails, my dear sir, it never fails. And yet, they never fail to remind me that I can do no right. They are so opportunistic that they never fail to profit from the knowledge accumulated by men through the ages. Or you promise me that you will never fail me again in any capacity, and we can all go on back about our evening. I Knew My Oldest Friend Would Never Fail Me.

they never fails me

112,500 results on the web

they never fail me

129,700 results on the web

More popular!

And yet, they never fail to remind me that I can do no right.
And they never fail to have some nimble talent.
Never fails, my dear sir, it never fails.
With this machine, the splendor of world should never fail.
Or you promise me that you will never fail me again in any capacity, and we can all go on back about our evening.
They are so opportunistic that they never fail to profit from the knowledge accumulated by men through the ages.
I Knew My Oldest Friend Would Never Fail Me.
A mother's instinct never fails.

And they never fail to have some nimble talent.
With this machine, the splendor of world should never fail.
A mother's instinct never fails.
Never fails, my dear sir, it never fails.
And yet, they never fail to remind me that I can do no right.
They are so opportunistic that they never fail to profit from the knowledge accumulated by men through the ages.
Or you promise me that you will never fail me again in any capacity, and we can all go on back about our evening.
I Knew My Oldest Friend Would Never Fail Me.