{"id":4330,"date":"2026-04-20T19:46:52","date_gmt":"2026-04-20T10:46:52","guid":{"rendered":"https:\/\/en.vietcafe-learning.com\/material\/?p=4330"},"modified":"2026-04-20T19:46:52","modified_gmt":"2026-04-20T10:46:52","slug":"grammar40","status":"publish","type":"post","link":"https:\/\/en.vietcafe-learning.com\/material\/grammar40\/","title":{"rendered":"Grammar 40: Time Expressions: “When”, “Before”, “While”, “After”"},"content":{"rendered":"

In this lesson, we will learn expressions related to time: “khi”, “tr\u01b0\u1edbc khi”, “trong khi”, and “sau khi”.<\/p>\n

[When] = khi<\/span><\/h2>\n

In Vietnamese, [khi] means [when] or [at the time of].<\/p>\n

Khi\u3000<\/strong><\/span>+<\/strong>\u3000Complete Sentence \u2460\u3000+\u3000,\u3000<\/span>+<\/strong>\u3000 Complete Sentence \u2461<\/strong><\/span><\/div>\n
or<\/div>\n
\n
Complete Sentence \u2461\u3000+\u3000khi<\/span>\u3000<\/span>+\u3000 Complete Sentence \u2460<\/strong><\/span><\/div>\n<\/div>\n

*If the subject is the same in both sentences, the subject of the first sentence can be omitted.<\/p>\n

Example Sentences<\/h3>\n
\n

\u2460 Khi<\/span> c\u00f3 th\u1eddi gian, t\u00f4i hay \u0111i d\u1ea1o v\u1edbi ng\u01b0\u1eddi y\u00eau.
\n\u3000When I have time, I often go for a walk with my partner.<\/p>\n

\u2461 T\u00f4i \u0111\u00e3 r\u1ea5t shock khi<\/span> m\u1edbi \u0111\u1ebfn Vi\u1ec7t Nam.
\n\u3000I was very shocked when I first arrived in Vietnam.<\/p>\n

\u2462 Khi<\/span> b\u1ed1 \u0111i l\u00e0m, t\u00f4i v\u1eabn \u0111ang ng\u1ee7.
\n\u3000When my dad goes to work, I am still sleeping.<\/p>\n

\u2463 Khi<\/span> th\u1eddi ti\u1ebft \u0111\u1eb9p, t\u00f4i th\u00edch \u0111i picnic v\u1edbi b\u1ea1n b\u00e8.
\n\u3000When the weather is nice, I like to go on a picnic with friends.
\n\u3000*Since the subject is the same in both clauses, it can be omitted.<\/p>\n<\/div>\n

[Before] = tr\u01b0\u1edbc khi<\/span><\/h2>\n

By placing [tr\u01b0\u1edbc] (before) in front of [khi], it means [before doing…].<\/p>\n

\n
Tr\u01b0\u1edbc khi\u3000<\/span>+\u3000Complete Sentence \u2460\u3000+\u3000,\u3000<\/span>+<\/strong>\u3000Complete Sentence \u2461<\/strong><\/span><\/div>\n<\/div>\n
or<\/div>\n
\n
Complete Sentence \u2461\u3000+\u3000tr\u01b0\u1edbc khi\u3000<\/span>+\u3000 Complete Sentence \u2460<\/span><\/strong><\/div>\n<\/div>\n

Example Sentences<\/h3>\n
\n

\u2460 Tr\u01b0\u1edbc khi<\/span> \u0111i ng\u1ee7, anh \u1ea5y th\u01b0\u1eddng nghe nh\u1ea1c.
\n\u3000Before going to bed, he usually listens to music.<\/p>\n

\u2461 Tr\u01b0\u1edbc khi<\/span> \u0111\u1ebfn Vi\u1ec7t Nam, t\u00f4i \u0111\u00e3 t\u1eebng s\u1ed1ng \u1edf Trung Qu\u1ed1c 5 n\u0103m.
\n\u3000Before coming to Vietnam, I lived in China for 5 years.<\/p>\n

\u2462 H\u1eb1ng ng\u00e0y, m\u1eb9 th\u01b0\u1eddng n\u1ea5u b\u1eefa s\u00e1ng cho t\u00f4i tr\u01b0\u1edbc khi<\/span> \u0111i l\u00e0m.
\n\u3000Every day, my mom usually cooks breakfast for me before I go to work.<\/p>\n

\u2463 Ch\u1ecb h\u00e3y g\u1ecdi cho t\u00f4i tr\u01b0\u1edbc khi<\/span> ch\u1ecb \u0111\u1ebfn nh\u00e9.
\n\u3000Please call me before you arrive.<\/p>\n

\u2464 Tr\u01b0\u1edbc khi<\/span> gi\u00e1m \u0111\u1ed1c quay l\u1ea1i, t\u00f4i s\u1ebd v\u1ec1 tr\u01b0\u1edbc.
\n\u3000Before the director returns, I will leave first.
\n\u3000*If the subject is the same in both clauses, it can be omitted.<\/p>\n<\/div>\n

[After] = sau khi<\/span><\/h2>\n

By placing [sau] (after\/behind) in front of [khi], it means [after doing…].<\/p>\n

\n
Sau khi<\/span>\u3000+\u3000Complete Sentence \u2460\u3000+\u3000,<\/span>\u3000+\u3000Complete Sentence \u2461<\/strong><\/span><\/div>\n<\/div>\n
or<\/div>\n
\n
Complete Sentence \u2461\u3000+\u3000sau khi<\/span>\u3000+\u3000 Complete Sentence \u2460<\/strong><\/span><\/div>\n<\/div>\n

Example Sentences<\/h3>\n
\n

\u2460 Sau khi<\/span> cu\u1ed9c h\u1ecdp k\u1ebft th\u00fac, t\u00f4i s\u1ebd \u0111i \u0110\u00e0 N\u1eb5ng ngay.
\n\u3000After the meeting ends, I will go to Da Nang immediately.<\/p>\n

\u2461 Sau khi<\/span> ch\u1ea1y b\u1ed9, anh \u1ea5y kh\u00f4ng \u0111i t\u1eafm.
\n\u3000After jogging, he does not take a shower.<\/p>\n

\u2462 Sau khi<\/span> c\u00f4 \u1ea5y n\u00f3i chia tay, t\u00f4i \u0111\u00e3 r\u1ea5t bu\u1ed3n
\n\u3000After she said she wanted to break up, I became very sad.<\/p>\n

\u2463 Em \u1ea5y s\u1ebd \u0111i du h\u1ecdc sau khi<\/span> t\u1ed1t nghi\u1ec7p.
\n\u3000After graduating, she will study abroad.<\/p>\n

\u2464 T\u00f4i r\u1ea5t mu\u1ed1n n\u1ea5u th\u1eed m\u00f3n n\u00e0y sau khi<\/span> xem c\u00f4ng th\u1ee9c n\u1ea5u.
\n\u3000I really want to try cooking this dish after looking at the recipe.<\/p>\n<\/div>\n

[While \/ During] = trong khi<\/span><\/h2>\n

By placing [trong] (inside) in front of [khi], it means [while] or [during].<\/p>\n

\n
Trong khi<\/span>\u3000+\u3000Complete Sentence \u2460\u3000+\u3000,<\/span>\u3000+\u3000Complete Sentence \u2461<\/strong><\/span><\/div>\n<\/div>\n
or<\/div>\n
\n
Complete Sentence \u2461\u3000+\u3000trong khi<\/span>\u3000+\u3000 Complete Sentence \u2460<\/span><\/strong><\/div>\n<\/div>\n

Example Sentences<\/h3>\n
\n

\u2460 Trong khi<\/span> t\u00f4i \u0111ang n\u00f3i chuy\u1ec7n, c\u00f4 \u1ea5y \u0111\u00e3 v\u1ec1 m\u1ea5t r\u1ed3i.
\n\u3000While I was talking, she already left.<\/p>\n

\u2461 Trong khi<\/span> \u0103n c\u01a1m, anh \u1ea5y hay xem ti vi.
\n\u3000While eating, he often watches TV.<\/p>\n

\u2462 Trong khi<\/span> anh Minh \u0111ang n\u00f3i chuy\u1ec7n v\u1edbi kh\u00e1ch h\u00e0ng, (th\u00ec) gi\u00e1m \u0111\u1ed1c \u0111\u1ebfn.
\n\u3000While Mr. Minh was talking to the client, the director arrived.<\/p>\n

\u2463 T\u00f4i g\u1eb7p ng\u01b0\u1eddi y\u00eau c\u0169 trong khi<\/span> \u0111i du l\u1ecbch \u1edf H\u00e0 N\u1ed9i.
\n\u3000I ran into my ex while traveling in Hanoi.<\/p>\n

\u2464 M\u1eb9 t\u00f4i \u0111\u00e3 d\u1ecdn ph\u00f2ng c\u1ee7a t\u00f4i trong khi<\/span> t\u00f4i \u0111i l\u00e0m.
\n\u3000My mom cleaned my room while I went to work.<\/p>\n

Note: For all of these structures [khi ; tr\u01b0\u1edbc khi ; sau khi ; trong khi], the conjunction [th\u00ec] (then) is sometimes placed between the first and second clauses. Adding [th\u00ec] smoothly connects the timeline of the two clauses and adds emphasis to the statement.<\/p>\n<\/div>\n

Practice:<\/h2>\n

Let’s try translating the following sentences with your teacher.<\/p>\n

\u2460 Khi c\u00f3 th\u1eddi gian th\u00ec t\u00f4i hay \u0111\u1ebfn hi\u1ec7u s\u00e1ch.
\n\u2461 Tr\u01b0\u1edbc khi \u0111i l\u00e0m th\u00ec anh \u1ea5y th\u01b0\u1eddng \u0111\u1ecdc b\u00e1o.
\n\u2462 Sau khi g\u1eb7p kh\u00e1ch h\u00e0ng th\u00ec t\u00f4i s\u1ebd \u0111i H\u00e0 N\u1ed9i ngay.
\n\u2463 Trong khi \u0103n c\u01a1m th\u00ec anh \u1ea5y hay xem ti vi.<\/p>\n\n\n

\n