Place your tongue tip near the roof of your mouth behind your top teeth. Push air through the narrow gap. No voicing.

Americans pronounce sign as SAHYN (/saɪn/). You'll hear it in sentences like "Do I need to sign this form here?" or "The bat is on the bed, which is a bad sign" — more examples below.
Record yourself saying "sign" 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.
Place your tongue tip near the roof of your mouth behind your top teeth. Push air through the narrow gap. No voicing.

Start with your jaw open wide and your tongue resting low and flat. Glide the front of your tongue up toward the roof of your mouth as your jaw closes halfway.
Touch the tip or front edge of your tongue to the roof of your mouth behind your teeth. Air flows through your nose.

Click any sentence to see the full breakdown — every link, every reduction, every flap-T.