Idioms: relationships

Dear Passengers,

We have been dealing with idioms related to family and relationships. Now that you know the meaning of an idiom cannot be understood literally but figuratively, the question is: what do the following idioms have in common? Using your own words, explain the general meaning of all of them in a comment.

Take one of them and write a sentence using it in context.

- birds of a feather flock together

- see eye to eye

- move in the same circles

- to be on the same page/wavelength

- speak the same language