Using 无意 as an adverb and a verb
The modal verb 无意
Pay attention
Modal verbs (情态动词) can be used to express possibility, desire, ability, and necessity. Modal verbs cannot appear without a predicate and can only appear in predicate phrases.
We use 无意 
to emphasize that a person doesn’t have a desire to do something.
to emphasize that a person doesn’t have a desire to do something.Examples
我无意去参加婚礼
I have no intention of going to the wedding
wǒ wúyì qù cānjiā hūnlǐ
我无意打扰您，不过我可以跟您谈一会儿吗？
I don't mean to disturb you, but can I talk to you for a moment?
wǒ wúyì dǎrǎo nín, búguò wǒ kěyǐ gēn nín tán yíhuìr ma
他既然无意参加，你就不要再勉强他了
Since he has no intention to participate, you shouldn’t push him
tā jìrán wúyì cānjiā, nǐ jiù bú yào zài miǎnqiǎng tā le
The adverb 无意
Sometimes 无意 can also act as the adverb “unintentionally”, “inadvertently”.
Pay attention
In this case, 无意 is usually followed by 中 .
.
Examples
她在收拾花园时，无意地找到了这只耳环
She found this earring by accident when she was cleaning up her garden
tā zài shōushi huāyuán shí, wúyì de zhǎodào le zhè zhǐ ěrhuán
昨天出去散步时我无意中遇到了他
I randomly bumped into him yesterday when I was out for a walk
zuótiān chūqù sànbù shí wǒ wúyì zhōng yùdào le tā
我无意中发现了一个秘密
I accidentally discovered a secret
wǒ wúyì zhōng fāxiàn le yí ge mìmì