“R” is a letter that every foreigner hates in Spanish, but not always is strong pronunciated.
When “R” is at the end of a word the pronunciation is always soft, and when is in the middle of the word the same.
Only two cases has the strong (hard) pronunciation, when starts any word: like “Reunion”, or when in the middle we have two “RR” together: like “Ferrocarril”.
To pronunciate the “R” there are 3 things that you can do:
1) Eliminate tension in the tongue.
You can move it from side to side, and then practice saying T as fast as you can, many times.
2) Get used to the right position.
Touch the palate with the tip of the tongue but without squeezing. The most similar position is like “D” or “T”, so you can use these consonants to get closer to the one you want. Then try saying “TR” or “DR”.
3) Practice, practice and practice.
You have to be patient and practice daily, without that it is impossible for anyone to get it right. After practicing every day for a few weeks, you will see how you get it!!
And now some writen exercises: