The word "learnable" is correct and usable in written English
You can use it to describe something that can be taught or learned. For example: "This material is highly learnable; it's easy to understand and absorb."
However, more recent results have shown that under different (and in many ways more plausible) assumptions about the learning algorithm, the class of natural languages and the correct criterion for learnability, natural languages are learnable from text.
Syllabaries such as the Cree syllabary are reported to be learnable in a day, while the indigenous Vai syllabary used in Liberia and Sierra Leone is learned in a few days.
But pictographic signs and logographic scripts with a limited readily learnable set of graphs are restricted to expressing a limited range of meanings.
More important, many terms learnable through demonstration apply to unobservables in Putnam's telling example, even small children learn to talk of "people too little to see".
Valiant's most-notable paper, "A Theory of the Learnable" (1984), provided a mathematical foundation for describing how a computer could learn.
Every middle-class Victorian young lady could draw, play piano, write poems, these are all very learnable skills.
Some psychologists, myself included, argue that empathy is less a fixed trait, like height, than a learnable skill, like Scrabble.
The technical skills are learnable; English majors can take computer-science courses.
These are learnable, teachable skills with which women will take our fair and equal share of leadership positions without the culturally driven self-limitation that has held us back.
Social skills were broken down into discrete, learnable units.
Lemov's view is that getting students to pay attention is not only crucial but also a skill as specialized, intricate and learnable as playing guitar.
