ASL grammar differs significantly from English, and facial expression is essential rather than optional. Facial features function as grammatical markers: raised brows and a slight forward head tilt indicate a yes/no question, while furrowed brows mark a wh- question (who, what, where, when, why, or how). Mouth morphemes are specific mouth shapes that accompany signs to add adverbial meaning; for example, the "cha" shape can indicate that something is very large. Mouthing spoken English while signing ASL is discouraged because it creates a hybrid that does not represent either language authentically.
Tense is handled with time signs and adverbs rather than verb conjugation. PAST is added at the beginning of a sentence or used as a time marker, FUTURE appears at the end or moves forward away from the signer, and NOW or TODAY uses the chin location to anchor present-time signing. YESTERDAY moves a hand backward over the shoulder, while TOMORROW moves it forward into an arc. Once the time is established, the rest of the sentence unfolds within that temporal frame.
Pronouns in ASL narratives often point to a specific location in signing space rather than repeating the word each time. After establishing a referent with a point or a sign, the signer can simply gesture back to that same spot to mean "he," "she," or "they." Role shifting, sometimes called constructed dialogue, allows a signer to physically shift their body and sign from the perspective of a specific character to represent dialogue in a narrative. Classifier handshapes, meanwhile, replace nouns and verbs in descriptive passages to show how objects move, look, or are arranged in space.