Jolly phonics is a method for teaching the sounds of English to children. It was developed a few years ago, and has been packaged for sale. It uses a simple system for transcribing sounds.
The IPA alphabet is a method of transcibing all the sounds in world languages, so that each symbol corresponds to one sound, and each sound has only one symbol. There are other phonetic alphabets like this, but the IPA alphabet has the most support. IPA is not a teaching method.
"IPA" actually refers to the International Phonetic Association, which developed the symbols. These symbols have been used for a hundred years or so, with some modifications.
International Phonetic Association - Wikipedia, the free encyclopedia
IPA doesn't need advertising. Their material is freely available.
Jolly phonics is a teaching method developed by a private company. You have to pay for it - that's why they advertise.
There is absolutely no need to pick up the "Jolly phonics" technique.
Do you already have a technique that teaches the sounds of English correctly to your students? If yes, then you don't need Jolly phonics.
You could download all their free material and use some of their methods if you find them useful - for example "The Actions" in their free information download might be useful. But you definitely do not have to buy all of the products they are advertising - that is, unless you decide to use the method.
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