en_tn/gen/11/06.md

one people with the same language

All the people were one big group and they all spoke the same language.

they are beginning to do this

Possible meanings are 1) "they have begun to do this," meaning that they have begun to build the tower but it is not finished, or 2) "this is just the first thing they have done," meaning that in future they will do greater things.

nothing that they intend to do will be impossible for them

This can be stated in positive form. Alternate translation: "anything they intend to do will be possible for them" or "they will be able to do anything they want to do" (See: rc://en/ta/man/translate/figs-doublenegatives)