It’s a common occurrence that the first sign your baby learns, whatever it happens to be, becomes the sign for everything. For example, if your baby learns to sign MILK first, he’ll use it to sign OUTSIDE, DAD, MOM, CEREAL, CRACKER and so forth. Basically the only sign your baby knows becomes everything they want!
As your baby gets going, your baby might also ‘over-generalize.’ Your baby will call all four-legged ANIMALS DOGS, when they might be CATS, HORSES and so forth. When this happens, it’s a symptom of lacking a sufficient vocabulary to do the sign for the things that interest them. Signing is the same as language where words such as BABY, BEAR, BOTTLE, and BALLOON sound similar and can become “ba-ba” in baby speak. You wouldn’t allow a baby to continue to use these words, or wouldn’t adopt these word replacements for your own language, so there’s no reason to allow your baby’s to sign the same thing for everything they want or see either.
Above: In the ASL sign for HORSE the thumb is brought up and touches the temple with the index and middle finger extended upward. The index and middle fingers then flap up and down representing a horses ears. This sign can be done with one or both hands.
These language errors are common and not a big deal, in fact it means that baby understands the association between language, and the things they want, as well as how to get them, or talk about them. What your baby doesn’t yet understand is that different things have different labels. The simple solution is to introduce new signs for the things they are expressing interest in, and continue to grow their vocabulary. Often the MORE sign ends up being used for a lot of different things. Instead of just guessing what your baby wants MORE of, you should instead ask your baby what they want MORE of. Ask baby if they want MORE APPLE, MORE BANANNA or MORE MILK. There’s nothing wrong with saying to a baby that you don’t understand what they want, or asking them to do the sign for the things they do want, especially if they already know the sign for it. This teaches your baby that there is a proper way to ask for things, and that you can’t just expect other people to know what they are thinking. If you child doesn’t yet know the sign, obviously this is a great time to teach it.