I swear on my children vs Promise

When to use each in English, with meaning, register, and examples.

I swear on my children

Informal Top 5,000 (fairly common)

Promise

Top 1,000 (very common) A2 verb

Most formal: Promise Most common: Promise

	I swear on my children	Promise
Pronunciation	🇬🇧 //aɪ swɛə(r) ɒn maɪ ˈtʃɪldrən// 🇺🇸 //aɪ swɛr ɑn maɪ ˈtʃɪldrən//	🇬🇧 /["/ˈprɒmɪs/","/ˈprɒmɪsɪz/","/ˈprɒmɪst/","/ˈprɒmɪsɪŋ/"]/ 🇺🇸 /["/ˈprɑːmɪs/","/ˈprɑːmɪsɪz/","/ˈprɑːmɪst/","/ˈprɑːmɪsɪŋ/"]/
Meaning	I promise strongly using my children as a reason.	A commitment to do something or not do something.
Example	I swear on my children, I will always protect them.	I promise to help you with your homework.
Register	Informal	Neutral
How common	Top 5,000 (fairly common)	Top 1,000 (very common)
CEFR level	-	A2
Part of speech		verb
Collocations	swear on my children, strongly swear, promise with sincerity, vow to protect, emphasize with family	faithfully, solemnly, initially, can, cannot, seem to, to, as promised, I can’t promise anything
Antonyms	-	lie, break, betray
Common mistakes	Confusion between 'swear on' and 'swear to'., Using in overly formal situations., Incorrectly using with abstract concepts.	Confusing 'promise' with 'vow' or 'pledge' in terms of strength., Using 'promise' without an object (e.g., 'I promise' should specify what)., Misusing in the past tense (e.g., 'I promised' without a follow-up).
Usage notes	Used in informal contexts to express strong promise or truth, often relates to personal feelings or beliefs.	Use 'promise' when you want to express a vow or assurance. Common in both spoken and written contexts, but avoid in formal legal documents.

See it in real clips

I swear on my children that he won't be, Mike.

I swear on my children

Avengers › Avengers Endgame

We promise to be careful.

and I always try to keep my promise.

And one system shows promise.

Avengers › Avengers Endgame

We promise to be careful.

and I always try to keep my promise.

Promise

Frequently asked questions: I swear on my children vs Promise

What's the difference between I swear on my children and Promise?

I swear on my children: I promise strongly using my children as a reason. Promise: A commitment to do something or not do something.

Which is more formal: I swear on my children and Promise?

Promise is the most formal of these.

Which is more common: I swear on my children and Promise?

Promise is the most common in everyday English.

Can you show an example of each?

I swear on my children: I swear on my children, I will always protect them. Promise: I promise to help you with your homework.

Can I use I swear on my children and Promise interchangeably?

Not always. I swear on my children and Promise are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.