The most common way to sign IF in ASL uses a single hand near your head: extend your pinkie finger (the “I” handshape), then tap the tip of your pinkie twice on the upper side of your forehead. But the hand sign alone is only half the story. In ASL, the word “if” is as much about your face and sentence structure as it is about your hands.
The Hand Sign for IF
Form your dominant hand into an “I” handshape by making a fist with only your pinkie finger extended. Bring your hand up to the side of your forehead and tap the tip of your pinkie against it twice in a short, light motion. This is the standard, widely used sign for IF in modern ASL.
You may occasionally see an older version of this sign that uses both hands in an “F” handshape (thumb and index finger touching in a circle, other fingers extended). In that version, both hands are held in front of you with palms facing each other, and they move up and down alternately, like the pans of a balancing scale. This sign dates back to at least 1910 and was common throughout the 20th century, but it’s largely fallen out of use today. If you see it, you’ll recognize it, but the pinkie-tap version is what you should learn.
Why Your Face Matters as Much as Your Hands
ASL uses facial expressions as grammar, not just emotion. Linguists call these “non-manual markers,” and for conditional sentences (if/then statements), they’re essential. Without the right facial expression, your IF sentence won’t read as conditional to a Deaf signer. It might just look like a statement or a question.
The non-manual markers for a conditional clause are: raised eyebrows, slightly widened eyes, and a head that tilts to one side or pushes slightly forward. You hold all of these throughout the entire “if” portion of your sentence, not just while signing the word IF itself. After the condition is complete, you pause briefly, return your eyebrows and head to a neutral position, and then sign the “then” part of your sentence with a normal or slightly nodding expression.
To see how powerful these markers are, consider that the sequence of signs JOHN BUY HOUSE can mean “John bought a house,” “Did John buy a house?”, or “If John buys a house…” depending entirely on what your face and head are doing. The grammar lives in your expression.
How to Build an IF/THEN Sentence
ASL conditional sentences follow a two-part structure. The condition (the “if” part) always comes first, followed by the result (the “then” part). You don’t need to sign a separate word for “then.” The shift in your facial expression from raised eyebrows back to neutral signals to the viewer that you’ve moved from the condition to the outcome.
Here’s an example. To say “If it rains tomorrow, we will cancel the game,” you would sign:
- IF clause: TOMORROW RAIN (with eyebrows raised, eyes wide, head tilted slightly, throughout both signs)
- Pause: A brief stop where your face returns to neutral
- THEN clause: GAME CANCEL (with a declarative head nod)
Notice that the English word order gets rearranged. The time reference (TOMORROW) comes first, the condition follows, and the result comes last. This is typical of ASL grammar, which tends to establish context and conditions before stating outcomes.
Timing Your Eyebrows
The most common mistake learners make is raising their eyebrows only while signing the word IF and then dropping them. Your eyebrows need to stay raised across every sign in the conditional clause. If your “if” clause is three or four signs long, your eyebrows are up for all of them.
The pause between the two parts of the sentence is also important. It’s not a long stop, just a beat. Think of it like the comma in the English sentence “If it rains, we’ll cancel.” That tiny break, combined with your face resetting to neutral, tells the viewer the condition is done and the result is coming.
You can also add emphasis when the condition is particularly important. A more forceful movement on the IF sign, direct eye contact, and a more pronounced eyebrow raise all signal to the viewer that the condition carries real weight, similar to how you might stress the word “if” in spoken English by saying it louder or slower.
IF vs. SUPPOSE
Some ASL signers use the sign SUPPOSE interchangeably with IF in conditional sentences. SUPPOSE uses a different handshape and location but serves the same grammatical function when setting up a hypothetical. In many ASL classrooms, you’ll see both used in conditional constructions, and in everyday conversation, fluent signers sometimes drop the manual sign for IF entirely and rely solely on the raised-eyebrow grammar to mark the clause as conditional.
This is one of the key things to understand about ASL: the non-manual markers are doing the heavy grammatical lifting. The hand sign for IF reinforces the meaning, but a fluent signer reading your sentence will identify it as conditional primarily from your face, your head position, and the pause between clauses. Getting comfortable with those markers is more important than perfecting the hand sign itself.