Experiment with online sequence-to-sequence neural machine translation model, such as translate.google.com/ or www.bing.com/translator or www.deepl. com/translator. If you know two languages well, look at translations between them. If you don’t translate into a language and then back to the language you do know. 

a. How well does the system handle very rare words? 

b. Does the system properly rearrange the order of words when necessary? 

c. Do the translations encode biases? 

d. How does the system do on very long sentences (over 60 words)?