Knock sb up Meaning, Examples & How to Use This Phrasal Verb

What Does “Knock sb up” Mean?

“Knock sb up” is a phrasal verb with two common meanings: to make someone pregnant or to wake someone up by knocking on their door.

Introduction

The phrase “knock sb up” can be confusing because it has different meanings depending on the context. The most common use is informal and means to cause a woman to become pregnant. However, in British English, it can also mean to wake someone by knocking on their door or calling them. Knowing the “knock sb up meaning” helps you avoid misunderstandings and use the phrase correctly in conversations. This guide will explain both meanings, provide examples, and show how to use “knock sb up” naturally in everyday English.

Quick Info Box

• Phrasal verb: knock sb up (knock somebody up)
• Type: transitive
• Level: B2 (Upper-Intermediate)
• Short meaning: 1) Make someone pregnant (informal) 2) Wake someone by knocking (British English)

Structure (Grammar Rules)

“Knock sb up” is a separable phrasal verb. You can place the object (sb) between “knock” and “up” or after the whole phrase.

• knock somebody up
• knock up somebody

Examples:

• He knocked her up last year. (make pregnant)
• Can you knock me up at 7 a.m.? (wake up)

How to Use “Knock sb up”?

Use “knock sb up” when talking about making someone pregnant in informal conversations. It is often used in casual speech and can be considered rude or too direct in formal settings. In British English, use it when you want to say you will wake someone by knocking or calling them, especially early in the morning.

Examples

Here are some natural sentences using “knock sb up in a sentence”:

• After dating for a year, he accidentally knocked her up.
• My neighbor knocked me up early this morning to remind me about the meeting.
• She was shocked when she found out he had knocked her up without telling her.
• Can you knock me up at 6 a.m. tomorrow? I have an early flight.
• He doesn’t want to knock anyone up without being sure they’re ready for a child.

Common Mistakes

People often confuse the meaning or use the phrase in the wrong context. Here’s how to avoid mistakes:

• Incorrect: I will knock you up tomorrow morning to talk about the project. (sounds like making pregnant)
• Correct: I will knock you up tomorrow morning to wake you up.
• Incorrect: He knocked her up in the office meeting. (too informal or inappropriate)
• Correct: He got her pregnant last year.

Differences / Synonyms

It’s important to know similar phrases and how they differ from “knock sb up.” For waking someone up, you can say “wake sb up” or “call sb up.” For causing pregnancy, “get sb pregnant” is a more polite and formal alternative.

• Knock sb up (informal, sometimes rude) – make pregnant or wake by knocking
• Wake sb up – simply to cause someone to stop sleeping
• Get sb pregnant – polite way to say cause pregnancy
• Call sb up – to phone someone or sometimes to wake by calling

Common Collocations

When using “knock sb up,” certain words often appear with it:

• knock somebody up early – wake someone early
• knock somebody up accidentally – cause pregnancy without planning
• knock somebody up at the door – wake by knocking on the door
• knock somebody up in the morning – wake someone in the morning

Related Phrasal Verbs

Here are related phrasal verbs of knock sb up:

• Knock Sth Together
• Knock About With Sb
• Knock Sth Back
• Knock Sth About
• Knock Sth Over

Real-life Dialogue

Here’s a short conversation using “knock sb up” naturally:

Anna: Can you knock me up at 7 tomorrow? I have an early meeting.

Ben: Sure! I’ll come by and knock on your door.

Anna: Thanks! I don’t want to be late again.

Practice

Fill in the blanks with the correct form of “knock sb up”:

• He accidentally _______ her _______ last year.
• Can you _______ me _______ at 6 a.m.?
• She was surprised when he _______ her _______ without telling her.

FAQs

• Q: Is “knock sb up” polite?

  A: No, it is informal and can be rude when referring to pregnancy.
• Q: Can “knock sb up” mean to wake someone?

  A: Yes, especially in British English, it means to wake someone by knocking or calling.

• Q: What is a polite alternative to “knock sb up” for pregnancy?

  A: “Get somebody pregnant” is more polite and formal.

• Q: Is “knock sb up” used in formal writing?

  A: No, it’s mostly used in informal speech.

• Q: Can I separate the words in “knock sb up”?

  A: Yes, you can say “knock her up” or “knock up her,” but the first is more common.