How to sign “Theory” in ASL
The BSL sign for “Theory” isn't in our dictionary yet — it will be fingerspelled in BSL mode, never replaced with this ASL sign.
Step by step
- Hold your dominant hand near the side of your forehead with your fingers extended and relaxed.
- Touch or hover at your temple, just beside your forehead.
- Wiggle your fingers in one small fluttering movement; a single wiggle is enough.
- Prefer this non-initialized version over the T-handshape variant, which some signers still use.
- Wear a thoughtful, serious expression, matching the weight of an abstract idea.
Practice tip
Same family as IDEA at the forehead — but the fingers wiggle in place instead of pulling out like a light bulb.
Fingerspell “Theory”
Letter by letter — a handy backup if you forget the sign above. This is not the sign itself.
Text-based guide researched from established ASL references (Lifeprint, university and public-health materials) and rewritten in original words. Signer-created photos and videos are a planned future upgrade.