Prepositions

since

Step 1: Identify that '2018' is a specific year (point in time). Step 2: 'Since' is used with specific dates or times as starting points. Step 3: 'For' is used with periods of time like 'for five years'. Step 4: 'From' needs to be paired with 'to' or 'till'. Step 5: 'Until' means 'up to a certain time' but doesn't fit this context.

by

Step 1: 'By' means 'not later than' or 'before or at a specific time'. Step 2: Example: 'Submit the assignment by Friday' means submit it any time up to Friday. Step 3: 'At' refers to a specific time only. Step 4: 'Until' means 'up to a time' but doesn't have the same deadline meaning. Step 5: 'Before' means earlier than, but 'by' includes the deadline time itself.

in

Step 1: Chennai is a large city. Step 2: 'In' is used with countries, cities, and large towns. Step 3: 'At' is used for small places, addresses, or specific points. Step 4: 'On' is used for surfaces, streets, or borders. Step 5: 'Beside' means next to something.

on

Step 1: The table is a flat surface. Step 2: 'On' is used for objects placed on surfaces. Step 3: 'In' would be used if the book were inside something enclosed like a bag. Step 4: 'At' is used for specific points or locations for activities. Step 5: 'Between' is used when something is in the middle of two things.