Prime Minister Theresa May has a very obvious 'tell'. It doesn't necessarily always indicate that she's lying, though. It sometimes indicates that she's aware that what she's offering is the opposite of what she's saying, and sometimes indicates that what she's offering is problematic but she's determined to push ahead with it anyway.
The 'tell' is the adverbs and adjectives she uses. For example, if she describes something as being "perfectly clear," then you can be pretty sure it won't be at all clear, especially in the case of Brexit. Even after negotiations have started, no one is at all clear on what kind of Brexit the UK wants. As lawyer and commentator David Allen Green has pointed out, something is either clear or it isn't. The word 'perfectly' is a smoke screen.
In the case of the protection of EU nationals living in the UK, May claims that she's made a "fair and serious" offer. But many EU nationals aren't convinced that it's fair, or that it goes far enough in protecting them. And many EU leaders are saying that it doesn't go far enough, despite Angela Merkel's statement that it's a good start.
It's worth checking the way Theresa May phrases her statements. She gives herself away very easily.
(For what the EU leaders are saying, check out the Guardian article linked below)
The UK needs to do more to reassure EU nationals about their future after Brexit, top official says.