What’s the difference between within and in?

What’s the difference between within and in?

'In' is a definitive and specific description of an object's location while 'within' describes an estimation. 'In' almost always refers to being inside with finality while 'within' requires parameters to be accurate. To make things easier to understand, look at this example: 'Elvis is in the building.'

Which tense is used with until?

When we use a negative construction (with not) in the main clause, until means 'not before'. We sometimes use the constructions have + past participle and had + past participle with until.

What is the difference between in and at?

The main difference between "in" and "at" in everyday speech and locating people or things geographically is this: … The preposition at is used to describe the fact of a person or thing being at a geographical location but does not describe the person or thing actually being inside of the structure or place.