Prepositions and connectors
Small words that link

- Prepositions show time and place: at, in, on, to.
- Connectors join ideas: and, but, so, because.
- They are small words, but they hold sentences together.
Prepositions of time: at / in / on
- at + a clock time / point: at 7 o'clock, at night.
- on + a day / date: on Monday, on May 1st.
- in + a longer period: in the morning, in July, in 2020.
- Small → large: at → on → in.
at, in or on? (time)
at a clock time, on a day/date, in a month/year/longer period.
Choose the correct preposition: The class starts ___ 9 o'clock.
A clock time uses “at”: at 9 o'clock.
Prepositions of place: at / in / on
- at + a point / place: at the bus stop, at home.
- in + an enclosed space: in the room, in China.
- on + a surface: on the table, on the wall.
Complete: The book is ___ the table. (surface)
A surface uses “on”: on the table.
Connectors: and, but, so, because
- and = adds; but = contrast; or = a choice.
- so = result: I was tired, so I went to bed.
- because = reason: She stayed home because it was raining.
- so gives the result; because gives the reason.
Choose the connector: She stayed home ___ it was raining.
“it was raining” is the reason → use “because”. (so introduces a result.)
Translate into English: 我累了,所以去睡觉了。
Result → so: “I was tired, so I went to bed.”
Common mistakes
- ❌ Because it was raining, so we stayed home. → keep only one: because or so.
- ❌ in Monday → ✓ on Monday; ❌ at July → ✓ in July.
- ❌ listen music → ✓ listen to music — don't drop the preposition.
at, on or in? Match the time.
at + clock time, on + day, in + month / year / season.
Which sentence is correct?
One connector is enough: “…, so we stayed in.” or “Because it rained, we stayed in.”
- Time: at (a time) → on (a day) → in (a month / year).
- Place: at (a point), in (inside), on (a surface).
- so = result; because = reason.
Write one sentence that gives a reason, using “because”. (For example: why you like something.)
Example: “I like winter because I can play in the snow.”