that is

USAGE SUMMARY

The phrase 'that is' is correct and usable in written English.
It is used to explain or clarify what you have just said. For example: I am taking an astronomy class this year - that is, a class about the stars.

✓ Grammatically correct

News & Media

Wiki

Human-verified examples from authoritative sources

Exact Expressions

60 human-written examples

That is sacrifice, that is service.

The Economist

"That is something that is missing.

The Guardian - Sport

Cornell fans, that is.

The New York Times

"That is something that is totally unique".

BBC

That is the bit that is missing.

Wikipedia

That is politics, and that is realism".

The New Yorker

That is all that is needed.

The New York Times

That is virtually gospel.

The New York Times

"That is just history.

The New York Times

That is our victory".

The New York Times

"Actually, that is weird.

Independent

Expert writing Tips

Best practice

Use "that is" to introduce a clarification or restatement of a preceding idea, ensuring clarity for your reader. Consider if a more concise alternative like "namely" or "i.e." might be suitable depending on the context.

Common error

Avoid using "that is" excessively in your writing, as it can make your prose sound repetitive. Vary your language by using alternatives like "in other words", "specifically", or rephrasing the sentence altogether.

Linguistic Context

The primary grammatical function of "that is" is as an adverbial phrase used for clarification or explanation. It serves to rephrase a preceding statement, providing further detail or making the meaning more explicit. Ludwig's examples show this function in various contexts.

Expression frequency: Very common

Frequent in

News & Media

70%

Wiki

15%

Formal & Business

5%

Less common in

Science

5%

Encyclopedias

3%

Reference

2%

Ludwig's WRAP-UP

In summary, the phrase "that is" is a versatile adverbial phrase used for clarification and explanation. As Ludwig AI confirms, it's grammatically correct and widely used, especially in News & Media. While useful for ensuring clarity, overuse should be avoided by considering alternatives like "namely" or "in other words". Its primary function is to rephrase previous statements, promoting precision and avoiding ambiguity. While generally neutral, its register can vary slightly depending on the context. By understanding its function and potential alternatives, writers can effectively use "that is" to enhance the clarity and precision of their writing.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

that is to say

Almost identical meaning, offering a slightly more formal tone.

in other words

Emphasizes rephrasing something for better understanding.

i.e.

Abbreviation for 'id est', a direct Latin equivalent used in writing.

which means

Highlights the consequence or implication of a statement.

namely

Provides a more formal and concise way to specify or identify something.

to put it another way

Implies offering a different perspective or explanation.

specifically

Highlights a particular detail or aspect.

put differently

Suggests explaining something in an alternative phrasing for enhanced understanding.

to be precise

Indicates a desire for greater accuracy and detail.

that being said

Introduces a contrasting or qualifying statement.

FAQs

How can I effectively use "that is" in a sentence?

Use "that is" to clarify a previous statement or provide additional context. For instance, "I'm studying astrophysics, "that is", the physics of stars and planets".

What are some alternatives to using "that is" in my writing?

Depending on the context, you can use phrases like "namely", "in other words", or "specifically" to clarify or restate information.

Is it correct to use "that is" at the beginning of a sentence?

While grammatically acceptable, starting a sentence with "that is" can sometimes sound informal or abrupt. Consider rephrasing the sentence for a smoother flow or using a more formal alternative like "in other words".

What's the difference between "that is" and "for example"?

"That is" is used to clarify or restate a point, whereas "for example" introduces an illustration of a point. Use "that is" when you want to make something clearer, and "for example" when you want to provide an instance or case.