Intimate social networks
close social networks
To talk shop
If people, who work together, talk about work when they are not at work.
To talk about business or work matters at a social event (where such talk is out of place).
On the tip of my tongue.
You're about to say what you know but you can't excactly remember it at the moment.
Loss for words.
If you can't say anything. Happens sometimes if you're surprised.
Talk the same language.
You're talking to a person, who has same ideas, same tastes, etc.
Look into something.
If you look into something, you may want to investigate.
You could also look into a box to check if you put everything outside of it.
Look after something.
If you take care of somebody or something.
In house training.
A training for employees is not at an education center, it is at the company itself (in house).