The adverbs of degree 十分 and 万分
Adverbs of degree (程度副词) are used to intensify or modify the degree of an adjective or verb.
We use the adverbs of degree 十分 
and 万分 to indicate the highest degree of something.
The adverb 万分 has stronger emotional coloring than 十分.
and 万分 to indicate the highest degree of something.
The adverb 万分 has stronger emotional coloring than 十分. Pay attention
It is easy to remember because 十 is translated as “10” and 万 as “10,000”.
These adverbs are usually used in written language.
Examples
万分感谢你把我从死亡中拯救出来
Thank you so much for saving me from death
wànfēn gǎnxiè nǐ bǎ wǒ cóng sǐwáng zhōng zhěngjiùchūlái
十分感谢你的支持！
Thanks a lot for your support!
shífēn gǎnxiè nǐ de zhīchí
We can only use 万分 with verbs or adjectives denoting feelings.
The adverb 十分 doesn’t have this type of restriction.
Examples
我万分高兴你这么快回我的邮件
I am very glad that you answered my email so quickly
wǒ wànfēn gāoxìng nǐ zhème kuài huí wǒ de yóujiàn
天气十分寒冷
The weather is extremely cold
tiānqì shífēn hánlěng