Other non-english speakers do this also. I think it is a learned pause.

It is a pet hate of mine
I record their voice and play it back to them and it seems to fix the problem in time
I get them to read allowed a page from a book into their phones as a kind of homework
This also gives them confidence and in time they put expression into their reading
Remember I am not a English teacher ( God knows i can't spell for shit ) But I know a lot about training exercise

It is a simple matter of cross-language transfer, common with native speakers of many languages learning English. As the English improves, the aspiration becomes less noticeable.

Yes it's a pet hate of mine and I will not accept it in the classroom from any age. Sometimes I can show them that by adding that sound to a word the meaning becomes completely different. But I simply don't let up and go one on one with students until the 'a' is dropped. Perseverance works and my students now know and consciously stop doing it when in my class.

I like that.

Yeah, this really confused me initially. My kindergarten students would do it all the time, and I wasn't sure if they were adding 啊 to the end of their words, or if they were mispronouncing them.

Most of the Chinese English teachers couldn't understand a lick of English, and those who could weren't able to answer that question, so I just made them repeat until the 啊 was gone.

EDIT: Fixed a bunch of tense mistakes. No why.

it is just impressive how the -ah is added to everything

Native "What your name"

Me "Chuck Norris"

Native "Nice meet you Chuck Norrisah"

The point being, you've just pronounced the name/word without ah, and the next second the ah is there. Aaaaarrrghhhh

Just like we are glad to have pinyin, the romanization of Chinese, and still fail to pronounce it properly, the Chinese quite often use their characters to 'sinifize' English and give themselves a clue as how to pronounce it. Thus, a word like breakfast might be remembered as 波乐可法斯特 or bolekefasite in pinyin. Since word endings in Chinese are either a vowel or -n and -ng, this method only enforces their natural inclination to insert eh's and ah's where they do not belong when speaking a foreign language.

The Chinese language does not allow for a syllable to end in a consonant other than an /l/ or an /r/. English, and most Germanic languages, have no such constraints, so when a Chinese speaker is confronted with a word that ends with a consonant, their first language pressures them to end the word with a schwa. It's not an uncommon L1 feature that pops up in ESL learners from lots of different languages.

You are going to find that Chinese people hardly ever become good English speakers.  Many Chinese English teachers teach their students really, really bad English.  My school told me to correct the Chinese teachers' English.  I brought up exactly what you are talking about.  They always call Erik Erika.  I told them this practice sounds really bad when native speakers hear it.  They just ignore anything I say and continue to teach students THEIR bad habits.  The other thing is... THEY try to tell me how to speak English!   They tell me the students don't understand me, never knowing that the reason for that is that their English is not good.  They need to hear me (or other native speakers) more so that they can understand REAL English!!