Granted it’s more or less the nightmare of every self-studying language learner if a textbook doesn’t provide an answer key. Most people suggest you find a native speaker but depending on where you live and how much time and money you want to invest, it can be really troublesome. Most native speakers don’t think it’s fun to correct your exercises and you need kind of a good relationship with them to get their help for free.
To fix that problem you can
- register on a language site and get an online language partner (the common case)
or if you absolutely don’t like to have any personal contact
- register on a language site like italki where you can post your exercises and some bored fellow will correct them for you
To ensure that your exercises get corrected, follow this advice:
- most people lose their motivation if they have to correct a whole page or something, so split up your exercises in just a few sentences and post them then