See Part – 1 for introductory contents – http://sunnyvarkeyk.com/question-tags-part-1/

Note:- A suggestion that uses ‘let us ‘ (let’s) uses ‘shall we?’ in the tag

• Let’s have a game of cricket, shall we? (P)

Note:- Although ‘everybody’ and ‘everyone’ are singular, they are usually treated as plural for the purpose of tag and referred to by ‘they’.

• Everybody can’t come in first, can they? (N)
• Everyone cheered wildly, didn’t they? (P)

Note:- ‘None of’ followed by a plural noun is treated as plural.

• None of the workmen arrived in time, did they? (N)
• None of us knew the way, did we? (N)
• None of the food was fresh, was it? (N)

Note:- The adverb ‘only’ may take either a positive or a negative tag. But, the positive is more usual.

• There were only six people present, were there? OR
• There were only six people present, weren’t there?