a little / a bit in negative

[Lee Sang]

I know the two senteces below are interchangeable.
The lecture was a bit boring.
The lecture was a little boring.
But I don't know if it is possible for the sentences below to interchange.
He was not a bit surprised.
He was not a little surprised.
Are they the same in meaning??

thanks

 

[lingobingo]

The second two mean the opposite of each other.

He was not a bit surprised = He was not in the least surprised

He was not [just] a little surprised = He was more than a little surprised; he was greatly surprised

 

[Lee Sang]

thank you, lingobingo