Frequency: The word is one of the 700 most common words in English.
1.
If something happens ~ a particular time, it happens during the period before that time and stops at that time.
Until 1971, he was a high-ranking official in the Central Communist Committee.
...consumers who have waited ~ after the Christmas holiday to do that holiday shopping.
= till
PREP: PREP n/prep
•
Until is also a conjunction.
I waited ~ it got dark...
Stir with a metal spoon ~ the sugar has dissolved.
= till
CONJ
2.
You use ~ with a negative to emphasize the moment in time after which the rest of your statement becomes true, or the condition which would make it true.
The traffic laws don’t take effect ~ the end of the year...
It was not ~ 1911 that the first of the vitamins was identified.
= till
PREP: PREP after neg
•
Until is also a conjunction.
The EU will not lift its sanctions ~ that country makes political changes.
= till
CONJ: CONJ after neg
3.
up ~: see up