The verbs 担保 and 保证 emphasize that someone is taking responsibility for his or her actions and guarantee that nothing bad will happen.
After the verb 担保, we can state either a verb or an entire sentence.
Nothing will happen, I can guarantee it
chū bù liǎo shì, wǒ gǎn dānbǎo
I guarantee she can do the job
wǒ dānbǎo tā néng zuòhǎo zhè xiàng gōngzuò
I guarantee there will be no problem
wǒ dānbǎo bú huì chū wèntí
After 保证, we can state either a noun, a verb or an entire sentence.
I can guarantee you that she is perfectly safe
wǒ kěyǐ xiàng nǐ bǎozhèng, tā juéduì ānquán
We guarantee the quality of our products
wǒmen yào bǎozhèng chǎnpǐn zhìliàng
The government pledged to support the program
zhèngfǔ bǎozhèng zhīchí zhè xiàng jìhuà
The noun 保证
We also can use 保证 as a noun with the meaning of “assurance", "guarantee”.
Buyers may need more assurance before paying
mǎizhǔ zài fùkuǎn qián yěxǔ xūyào gèng duō de bǎozhèng