A great tool to use for finding useful sentences is Tatoeba. Tatoeba is a large database of sentences and translations. The sentences are copyright free, and so Lingopolo may happily use them without any problem: there is just one condition, that we must link back to any sentence we use from Tatoeba. This link back is something which we must always do, as it is a condition of using content from Tatoeba.
For example, imagine that we want to add some sentences to Lingopolo for the Croatian word "stol" and we are lacking in ideas. We can search for "stol" on Tatoeba. Notice how we select to show only the English translation. Beware too that the blue arrow indicates a direct translation, and the grey arrow indicates an indirect translation. You should be careful to check any indirect translation with the grey arrow.
If you find a sentence which you would like to use, the best thing is to click on the English translation.
You can then get the URL which you will need in order to give the acknowledgement:
https://tatoeba.org/en/sentences/show/39635
You can now copy the English and the Target language text to Lingopolo.
When creating the entry on Lingopolo you can add the URL of the sentence page from Tatoeba:
