PocketSign
Basic

Mouth Morphemes Basics

A mouth morpheme is a specific mouth shape that adds meaning while your hands sign. It is different from silently mouthing English words.

All Mouth Morphemes lessons
ASL signer ready to teach mouth morphemes with a clear face and black top

Before You Start

These two ideas keep the lessons simple: the mouth shape has meaning, and it happens at the same time as the sign.

Not English mouthingDo not silently say the English word with your lips. Use the ASL mouth shape that matches the meaning.Example: OO can show small even if the English word is tiny, thin, narrow, or smooth.
Same time as the signStart the mouth shape with the sign it describes. The mouth shape should not appear after the sign is over.Think of the hands and mouth as one combined signal.

Learn It

Start with the simple version, then practice it with real signs.

In ASL, your mouth can do grammar work. A mouth morpheme is a mouth shape that changes or adds meaning to a sign.

Some mouth morphemes describe size, like very large or very small. Some describe how an action happens, like carefully or carelessly.

Start with a few common mouth shapes. Practice them slowly with easy signs before you try them in a fast conversation.

MeaningThe mouth shape adds meaning. It is not random expression.
TimingMake the mouth shape during the sign it belongs with.
ControlUse the shape when it helps the message, not on every sign.

Try It

Practice slowly. Make the mouth shape at the same time as the sign.

  1. Sign with a neutral mouth. Then sign with a big-mouth shape to show a huge house.
  2. Sign with a neutral mouth. Then sign with a TH mouth to show messy or careless writing.
  3. Pick one object near you and describe it with only one mouth shape: small, average, or huge.

Simple Examples

Read the ASL line first. A dark green pill names the mouth shape, not an extra sign.

ASL line . CHA mouth
MeaningThe house is huge.
TipThe mouth shape adds the feeling of very large.
Mouth actionCHA mouthOpen the mouth wide while signing the size idea.
ASL line . TH mouth
MeaningWriting carelessly or sloppily.
TipThe mouth shape shows the manner of the action.
Mouth actionTH mouthLet the tongue show slightly while the action looks careless.

Common Mistake

Do not mouth the English sentence while signing. That can cover up the ASL mouth shape the viewer needs to see.

Deeper Note

A little more grammar

Mouth morphemes are part of non-manual signals. Some work like adjectives, some work like adverbs, and some help show timing or result.