We don't say "¿Es la verdad?"
Maybe "¿Es verdad?" or "¿Es en serio?" or even the Mexican Spanish "¿Neta?"

I'd recommend contributing sentences in your own native language. You could be helping us much more that way, since people would be able to trust that what you have contributed is likely to be good and natural-sounding.

[#1230823] If you translate from your second language into your own native language, rather than the other way around, you're less likely to make mistakes.

[#1907470] It's very easy to sound natural in your own native language, and very easy to sound unnatural in your non-native language.

Even if some sentences by non-native speakers are good, it's really hard to trust that they are good, so members would be helping us much more by limiting their contributions to sentences in their own native languages. Remember that the purpose of the Tatoeba Project is to create example sentences that can be used for studying languages. It’s not really a place to be contributing non-native language sentences for others to correct for you.

[#3946394] We recommend adding sentences and translations in your strongest language. If you are interested primarily in having your sentences corrected, you should try a site like Lang-8.com, where that's the focus.

Ah, I understand D: I will try to stick to low-level Spanish sentences, rather than translating really tough ones. Thank you for diligently updating me on the rules and guidelines.