relationship/relation

English as a Second Language English Vocabulary, Grammar and Idioms
1
  1. I have established a good working relationship with my boss.
  2. I have established a good working relation with my boss.
    Are these two sentences OK?
    Do they mean the same or do they have any difference in meaning?
2

‘Relationship’ refers to a particular contact you have with someone. ‘Relation’ on its own refers more often to a member of your family - uncle, cousin and so on. In (2) it would be better to use the plural form when talking more generally and say: I have established good working relations with my boss.

3

Alan,
Is this chat OK?
Q: Is your boss any relation to you? A: No, he is not my relation/relative.

4

Yes.