It's probably more that I just don't get on with it. I found it really weird, odd sentences that they get you to translate.
Yeh the strange sentences; 'The cat married the elephant' and stuff like that.
BUt worse, the design of the Duolingo programme is poor, IMO, and I'm pretty proficient at languages. When you answer a question, if you get it wrong it just tells you the correct answer and you have to move on to the next question, eventually coming back to the one you got wrong again at the end.
This is poor pedagogy; when you make a mistake the first thing you should do is try and rectify it. When you make an error Duo should tell you you are wrong and let you try again, so you can think about it and try and spot what you did wrong and rectify it yourself, without seeing the correct answer. If you have a chance to do that you will probably not make that error again because it will be reinforced in your mind. Just telling you the correct answer is valueless.
Imagine you were in a classroom and your teacher asked you to say something and you stumbled; she wouldn't just tell you the right answer and move on, she'd give you a chance to get it right; profit from the error.
It's good that it is free and has lots of language choices, and new ones appearing all the time, but it's scuppering itself by the design of the teaching method, and those of you using it are being kept back from progressing quicker, unnecessarily.
The forums are an absolute disaster as well.