Sign language as a communication prosthesis with language-impaired children.

The team worked with children who had trouble learning language. They picked two small word groups: prepositions like "in" and "on," and pronouns like "he" and "she."

Each child got two kinds of teaching. Some lessons used only spoken words. Other lessons paired the spoken word with a simple sign. The teachers switched the order so they could see which way worked better.

Kids learned more words and remembered them longer when speech came with a sign. Prepositions gained more than pronouns.

Speech-only lessons helped a little, but the boost faded fast. Adding a sign made the new words stick.

Hicks et al. (2011) later showed you can teach prepositions without any signs. Their students still learned, so the sign boost is helpful, not required.

Bailey et al. (1990) tried the same speech-plus-sign idea through video tapes. Live teaching beat the video for sign production, proving the teacher in the room still matters.

DeVellis et al. (1979) taught labels first and saw receptive skills grow. Konstantareas (1984) flips the focus to little grammar words, showing the old "teach expressive first" rule works for functors too.

If a child is stuck on words like "in," "under," or "her," show a quick sign while you say the word. Pick a simple gesture you can do every time. Prepositions respond best, so start there. One extra motion can cut practice time and keep the skill for good.