Here are examples of word clouds that I created to highlight the im- prefix, and one based on a reading text.
The vocabulary one helps to highlight adjectives that form their opposite with im- by making them bigger than those using un- To do this, in the text creation box I typed the adjective once, the opposite with un- twice, and the opposite with im- three times.
The text example was pasted in without any modifications on my part, and you can see that the words technology, internet, natives and immigrants appear more frequently in the text - and digital is the most frequent item. You could use the word cloud to ask your learners to try to predict the text, based on the size (= frequency) of the words, for example.