Localization 

Translate versus Copy 

When translating a content element, TYPO3 offers two modes unless a project has explicitly opted into mixing them on the same page (mod.web_layout.allowInconsistentLanguageHandling in Page TSconfig):

• Translate creates connected records: each translation stays linked to its default-language source. Once a language column holds connected records, TYPO3 locks that column down: no new element can be created there, nothing can be pasted into it, and nothing can be dragged into or within it.
• Copy creates free records: independent translations with no link back to a source. A column of free records behaves exactly like a default-language column, with full drag and drop, paste, and new-element creation.

This choice is made once, per page and language, through TYPO3's own translation tooling; it is not a Grid Elements setting, and Grid Elements does not override or replace it. The lock on a connected column is TYPO3 Core's own, applied to the column as a whole, and it governs a Grid Element's own cells exactly as it governs a page column: an editor who needs to rearrange a Grid Element's children in a translated language needs that language in free (Copy) mode; a connected (Translate) language keeps the structure locked to whatever the default language already has.

Translating a Grid Element and its children 

A Grid Element's children are ordinary content records related to it through a dedicated parent-child relation, not through their position on the page, see Data Model. Nothing about that relation is specific to one language: a Grid Element and each of its children have their own translation state, exactly as any other content element would.

Two places in the backend deal with translating a Grid Element's children:

• The container's own edit form lists its children and offers TYPO3's usual localization controls there, letting an editor localize or synchronize individual children directly from the container.
• When a whole page's content is translated at once through TYPO3's page-wide translation tool, a Grid Element and its children are offered as a single unit rather than as separate top-level entries; a child already accounted for through its container is not listed again on its own. An editor does not need to individually select a container's children in that tool for them to be included.

Because none of this depends on any Grid Elements-specific TCA override, and both mechanisms build directly on TYPO3 Core's own inline-relation and page-translation handling, this behavior can be relied on across TYPO3 versions that support Grid Elements' underlying requirements. It is not something a future TYPO3 upgrade is expected to change without a corresponding Core change to connected/free localization itself.

For the architectural difference between Grid Elements and EXT:container localization, including why Grid Elements' relation model is one of the few places "Core-native" is a technically meaningful description, see Grid Elements and EXT:container.