The samples that follow all paraphrase, appropriately or inappropriately, this passage from page 94 of Language Visible: Unravelling the Alphabet from A to Z by David Sacks:

Your first year or two of life represent your golden chance to become bilingual, while your brain is malleable that way. Given the environment, you could grow up learning Hindi and Japanese, no problem – to say nothing of Spanish and English, relatively similar to each other, which is the most usual North American bilingual pairing. After about age two, if you learn a new language, you will probably fail to imitate perfectly those sounds you are not used to: Your brain is by then shutting down that department. You will speak the new tongue probably in a foreign accent, however slight.

Plagiarized paraphrase:

David Sacks points out that your initial year or two of life constitute your best chance to become bilingual, while your brain is changeable that way. Under such circumstances, you could grow up learning Hindi and Japanese, no problem – along with Spanish and English, relatively similar to each other, which is the standard North American linguistic pairing. When you are older than two, if you learn a new language, you will probably incorrectly pronounce those sounds you are not used to: Your brain is by then shutting down that area. You will speak the new language with an accent, however slight.

(Both the structure and some words of this passage resemble the original too closely for it to be an acceptable paraphrase).

Plagiarized paraphrase:

In early childhood, when the brain's wiring isn't all completely laid down, children will probably be able to learn additional languages – even languages like Hindi and Japanese. In contrast, children who learn languages later, when the brain's linguistic wiring is established, usually cannot master the pronunciation of sounds not found in their original language. In other words, languages learned later will always be spoken as foreign languages.

(This is plagiarism because no acknowledge is given to the source of these ideas.)

Acceptable paraphrase:

According to David Sacks, in early childhood, when the brain's wiring isn't all completely laid down, children will probably be able to learn additional languages – even languages like Hindi and Japanese. In contrast, Sacks notes, children who learn languages later, when the brain's linguistic wiring is established, usually cannot master the pronunciation of sounds not found in their original language. In other words, languages learned later will always be spoken as foreign languages (94).