I think they're injurious. I think they encourage laziness, and most people don't need any encouragement in that department.

Yeah, I agree with you. Actually, I think what makes it seem weird is the contrast between the words "suitable" and "injurious" when they're placed side-by-side in isolation. "Suitable" is as bland a word as you'll get; while "injurious" is 'fancy-sounding' owing to its lack of use in everyday speech. The ultimate effect being a jarring one. It just doesn't flow. 

I've seen the word "injurious" numerous times. Granted, it doesn't crop up that often in everyday speech, but it isn't overly formal. I think it's perfect for the title of a discussion. Although, its use in the actual title of this discussion seems a little off. I think it's because it sounds like whoever wrote it is trying too hard to squeeze in a "fancy" word where there's no real need to.

Anyway, "Is Auto-Correction Injurious to Language Learners?" would be a more natural sounding alternative.

I now use pad to writing, I just find that it is pity never used it since I bought it.

I think the function is auto-guess-word. Not bad

but the function of SPeech Sounds does not work on me, my mother language is no problem on google speech Sounds.

Azalea I'd never seen that word before until this thread so I can't really comment on how its perceived. To me, it seems too formal and I can't imagine a situation where I would this word myself. If you want to use another adjective rather than simply negate the word 'suitable', I would have gone for something like 'harmful' instead, which sounds more natural.

Anyway I don't want to hijack the original thread with this discussion, so I will offer a response to the original question.

If you use autocorrectors in the right way then they are a very useful tool. If you want to write something quickly on your phone, or simply check what you have already written for spelling mistakes that arise from typos software like this can be invaluable. The problem comes when people become over-reliant on the technology to correct their mistakes or lack of vocabulary, so if the technology isn't there then they may struggle.

For this reason I don't use them when I write something in a foreign language, I always use a dictionary if there's something I don't know how to express because you need to know the context of a word to use it appropriately.