就 (only / just — small quantity)

"Just that little"

• then / just就jiù can stress a small quantity: "only / just (that few)".
• then / just就jiùhe / him他tā一个yí gèperson人rén = "just him, alone"; then / just就jiùto remain剩shèngthese这些zhè xiē = "only these are left".
• Here then / just就jiù means "merely", not "then".

then / just就jiù + (small quantity)

• then / just就jiù before a small amount = "only that much".

only就jiùhim他tāone一yíperson个人gè rén。

• then / just就jiùhe / him他tā一个yí gèperson人rén = "(it's) just him, alone."

"Merely", not "then"

• This then / just就jiù highlights how few / little — different from the "then" then / just就jiù.

Recap

Read the full reference: HSK 4 grammar — Adverbs.