I have always loved the beauty and passion of sign language; over the years,
I had taken a few classes to learn ASL. I read about using it with babies, and decided to teach my baby basic signs when I had her. All of us used signing to communicate with her from the beginning, and she picked it up quickly.
It definitely cut down on her need to cry or whine or fuss to express herself. However, signing was never meant to be a substitute for learning spoken language; it was a bridge until she was physically capable of speaking.
We always said the words along with the signs, and it worked.
I wasn't sure she TRULY understood what she was doing – the connection between her hands and our actions – until she was six months old. She signed "Please" and pointed to her rattle, which I gave her… THEN, she put it down and signed, "Thank You" before she started to play!
She was just as precocious as her older brother in speaking early and clearly, and developing an extensive vocabulary – by three years old, we could have long talks together, and she would make and stick to detailed plans. Often, when I’d say no to something, she’d offer up a “Deal”!
At four, she attended a language-immersion preschool, set up to research how it would affect learning. One-third of the students in each class were Spanish-speaking only, one-third were Japanese-speaking only, and the last third was English-speaking only (that’s us).
Although my daughter didn’t, in the long run, retain any specific Japanese or Spanish words from that time, and although we gradually stopped using sign language as her spoken language skills grew, I am sure those experiences helped her brain develop extra neural connections, and contributed to her continuing passion for reading and education.
In my opinion - DO IT - and have fun with it!