I noticed that I can use "sometimes" In the beginning of the sentence and in the middle and at the end like this.

- sometimes I go there.
- I sometimes go there.
- I go there sometimes.

So, the question is
Can I use all the adverbs of frequency like ( Always - Usually - often - rarely - never )
In the beginning and in the middle and at the end of the sentence too??

And if so, does it sound natural in USA??

Question

I noticed that I can use "sometimes" In the beginning of the sentence and in the middle and at the end like this.

- sometimes I go there. 
- I sometimes go there. 
- I go there sometimes.

So, the question is 
Can I use all the adverbs of frequency like ( Always - Usually - often - rarely - never ) 
In the beginning and in the middle and at the end of the sentence too??

And if so, does it sound natural in USA??

Answer

Sometimes can be used in each of three position you mentioned. But it's different for all the other adverb of frequency. There are specific rules. If you need help with this topic I will be glad to help you in one of my class. 
Have a nice day

Answer

Unfortunately English is not very consistent.   I think in most cases the adverbs work in the middle or end, but not all of them work at the beginning.  I can't really think of any particular logic for which ones do and which ones don't.