In German there is a category of verbs called trennbare Verben (separable verbs), which are somewhat akin to English phrasal verbs and are mostly formed by a verb plus a preposition. The difference is that, unlike their English counterparts, German separable verbs are not always separated. Their infinitive and participial forms are always a single word. For example, the verb aufhören (stop/quit) is formed by the verb hören (hear/listen) plus the preposition auf (on), and its participle is aufgehört. Here is a comparison between the conjugated forms of the base verb and the separable verb:
Hör mich! = listen to me!
Hör damit auf! = stop it!
As you can see, the preposition goes at the end. And it can get even worse:
Hör mit dem Lügen auf! = Stop with the lies!
Hör mit diesem verdammten Getrommel gegen die Wand auf! = Stop that damn banging on the wall!
I understand it would be almost impossible to automatically detect if the preposition is working together with the verb or not. But it would be awesome if you could allow users to link those two words manually on a case-by-case basis. That would avoid having incorrect examples being linked to the base verb and it would help people reading public texts which have already been annotated by someone.