Dobrý den,

dá se přeneseně použít spojení – “parasitize on sth”? Třeba ve větě “The may parasitize on your success.”?

Našel jsem, že to sloveso existuje, ale v tomhle spojení jsem to až na pochybné výjimky nikde nenašel. 

Parasitise (AmE parasitize) on does exist and you could (theoretically) use it metaphorically and it would be understood, but it doesn't sound natural and it's unlikely that a native speaker would say it, given the availability of several good and idiomatic alternatives with pretty much the same meaning, i.e.:

• He may try and/to capitalise on your success (for his own gain)
• He may try and/to profit from your success
• He may try and/to exploit your success (for his own gain)
• He may try and/to cash in on your success
• He may try and/to freeload on the back of your success

Will these companies contribute back to the community in any meaningful way, or just freeload on the back of the platform? (shareable.net)

• He may try and/to freeload off the back of your success

Apple has accused Australia's big banks of attempting to freeload off the back of its investment into Apple Pay (itnews)

You can say 1. try and do something, or 2. try to do something. There's no difference in meaning, but in terms of style, 1 is probably more likely in conversation, 2 is more likely in writing.

As you see, you can freeload on the back of something, or freeload off the back of something. The meaning is the same.

Ty jo, suprově vysvětlený, mockrát díky!