Just

Adverb

only, simply

Syntax

just triggers the use of perfective aspect (have + -en) when it marks a recently accomplished prior action.

• I had just finished eating when the doorbell rang.
• I've just left work. I should be back home in an hour.

In both the UK & the US the past perfect is used with just to mark a recently accomplished prior past action.

In American English the simple past is frequently used instead of the present perfect.

degree modifier

"just now" = precisely now. "just then" = à ce moment précis

just can qualify a preposition in many of the same ways "right" can:

• The boss always naps just after lunch.
• He usually makes weak coffee, but this cup is just right.
• She smelled the fire just in time to still be able to put it out.
• They live just over the hill there.

speech softener

"just" is often used when making a suggestion, when criticizing, when explaining one's intentions/reasoning...

• I'm just wondering if we should even continue producing these books, we keep losing money on them.
• just saying (je dis ça, je dis rien)
• I just wanted to say thank you!
• I just thought it wasn't a big deal. I didn't realize it was so important.

Adjective

fair, equitable