instruction:
Rewrite each original sentence in order to make it easier to understand by non-native speakers of English. You can do so by replacing complex words with simpler synonyms (i.e. paraphrasing), deleting unimportant information (i.e. compression), and/or splitting a long complex sentence into several simpler ones. The final simplified sentences need to be grammatical, fluent, and retain the main ideas of their original counterparts without altering their meanings.
question:
The Tuvaluan language is spoken by virtually everyone, while a language very similar to Gilbertese is spoken on Nui.
answer:
Almost everyone speaks Tuvaluan. However, a language very similar to Gilbertese is spoken in Nui.

question:
Cave himself often contributed pieces to the Magazine under the pen name of Sylvanus Urban.
answer:
Cave often gave pieces to the Magazine. He used the pen name Sylvanus Urban.

question:
Together they had 18 children, of whom 11 survived to adulthood.
answer:
They had 18 children, only 11 survived.