Prepositions of time "by" and "until"

source: Crown Academy of English      2016年6月27日
In this English grammar lesson, you will learn how to use the prepositions of time "by" and "until" as well as some related common time expressions.

In general, "by" + a specific time describes something that must happen before a deadline.
"until" + time expression indicates the duration of a continuous action or event up to a specific moment in time.
I also explain "till" and when we use it.
These prepositions of time are very common and important in English and so, at the end of the video, there is a quiz to test your understanding.
Related videos:
Prepositions of place: http://www.youtube.com/watch?v=_zhw3B...
Conditionals: http://www.youtube.com/watch?v=WPDpe_...