Englishfor English speakers
under
Preposition
—
In the same place as another thing, but lower.
They ate under the trees.
—
In the control of.
He was under the leader of the organization.
—
In the middle of a process; experiencing.
The idea is under the committee's judgement (judging).
the
Determiner
—
Used, instead of a, to reference something specific, already known to exist.
Compare "I read a book." and "I read the book."
—
Used with a stress, to show that the word following is special.
Are you the John Smith that I went to school with?
—
Used with an adjective that acts like a noun to mean all of the people concerned
The poor are always with us.
—
Used with superlatives forms of adjectives and adverbs.
You are the best.
assumption
Noun
—
An assumption is a guess or belief about something without having enough information to know if it is true. In maths or science: something assumed to be true in order to build an argument or calculation.
You shouldn't make the assumption that guns are only a problem in big cities.
To calculate the age of a rock we make the assumption that the rate of radioactive decay is constant.