Study the phrases about relationships.
To be in a relationship - to be romantically involved with someone;
To be just good friends - to not be romantically involved;
To keep in touch with - to keep in contact with;
To lose touch with - to not see or hear from someone any longer;
Love at first sight - to fall in love immediately you meet someone;
To pop the question - to ask someone to marry you;
To see eye to eye - to agree on a subject;
To settle down - to give up the single life and start a family;
To strike up a relationship - to begin a friendship;
To tie the knot - to get married;
To be well matched - to be similar to;
To work at a relationship - to try to maintain a positive relationship with someone.
Examples:
We are just good friends.
Do you believe in love at first sight?
Sally is in a relationship with Mike.
It is essential to work at a relationship.