Raise the back of your tongue to touch the soft palate. Add vocal cord vibration, then release.

Americans pronounce grew as GROO (/gru/). You'll hear it in sentences like "The gross domestic product grew at an annual rate of three percent".
Record yourself saying "grew" and play it back. The mic stays on your device — nothing's uploaded.
1 syllable, 3 sounds. Explore each sound's mouth shape and how it's made.
Raise the back of your tongue to touch the soft palate. Add vocal cord vibration, then release.

Curl or bunch your tongue without letting the tip touch the roof of your mouth. Brace the sides of your tongue against your upper back teeth, and round your lips slightly.
Round your lips into a tight circle. Let your tongue rest in the middle of your mouth, slightly raised.