American speakers pronounce R by making the tongue tense. When the tongue is tense, the throat naturally becomes a little bit tight. Make sure that the tip of the tongue does not touch the top of the mouth.
In grade schools, American teachers compare the R to a growling sound made by a cat. If you think of that, it could help you to tense the tongue and throat in the right way.
You can also think of the consonant Y sound as in yes. With this sound, we tense the tongue just a bit. R is made in about the same way except the tongue is much tenser.
If you are not used to this R sound, you just need practice. Remember: Americans pronounce all R sounds–whether R is first, middle or last.
Use the video to listen and repeat common words.
Before, Course, Door, Floor, For, Force, Fork, Form, Four, Horse, More, Morning, North, Order, Port, Short, Story, War, Warm, Your.