Point 1: In

Giới từ In được sử dụng trước danh từ mà chủ yếu đề cập đến thời gian (thường là khoảng thời gian dài) và nơi chốn (những đia điểm lớn)
The preposition "in" is used before a noun that mainly refers to time (usu. a long period of time) and place (usu. big)

A. Thời Gian

  • in + year, century, era

in 2006, in the 19th century, in the 1970s

  • in + month, season

in January, in the summer. (Note: on January 5th)

  • in + part of a day.

in the morning/afternoon/evening
Note : at dawn, at noon, at night

B. Place

  • in + place (usu. big)

in the world, in the univese

  • in + names of oceans, continents

in the Pacific, in Asia

  • in + names of countries, states, cities.

in Korea in California in Seoul

  • in + neighborhoud/surburb....

in the neighborhood (of) in the suburbs (of)

C. Other uses

* in + language

in English, in Spanish, in Korean

* in + newspaper, magazine.

in the newspare Note: on TV on radio.

* in academic subject, field of expertise, industry.

in science, in chemical engineering

* in + department/division (of a company)

in the accounting department
in the public relations department

* in + means of transport
in(on) a tax Note: by taxi

D. Some idiomatic expressions with in

in my opinion
in the future
in the rear of
in danger of
in general
in particular
in person
in a row
in the past
in season: chỉ thời điểm vào mùa, vào mùa (trái cây, rau) => out of season: không trúng mùa
in session => out of session
in stock: còn hàng => out of stock: hết hàng
in print : được xuất bản, được in => out of print: hết được xuất bản
in front of
in the middle of

be in the middle of (doing) something: be busy doing something - Can I call you back - I am in the middle of the meeting
be in the middle of something: if you are in the middle of something, it is happening to you or around you

in the meantime :trong lúc đó
in the period of time between now and a future event

in the end
in detail
in line
in part
in time

Point 2 : ON

Giới từ on được sử dụng trước danh từ mà đề cập đến nơi chốn, không gian và khoảng thời gian cụ thể


* on + date, specific period of time
on October 9
on that day
on the morning of October 8

*on + day
on Friday, on Saturday

B. Place, space

* on+ street
on Wall Street

* on+ space, surface

on the wall
on the floor
on the ceiling
on the cover

C. Some idiomatic expressions with "on"

on foot
on vacation
on the market
on time
on duty
on a map
on the other hand
on strike
on the wane
on a business trip
on sale: được bán giảm giá
on schedule: theo đúng lịch trình, theo đúng kế hoạch
on a diet
on leave
on air
on purpose
on top of