1
Are you a member of the club?
To ask this, sign 'you', then 'member', and finally 'club'. Since this is a yes/no question, remember to raise your eyebrows and lean forward slightly while holding the last sign to clearly show you are asking for a response.
2
She is a new board member.
For this sentence, you would sign 'she', 'new', 'board', and then 'member'. Keep your signing space organized and ensure the 'M' handshape for 'member' is distinct from the 'B' handshape used when signing 'board'.
3
How many members are in your family?
Sign 'your', 'family', 'member', and then 'how-many'. Because this is a 'wh-' question (asking 'how many'), you need to furrow your eyebrows and tilt your head slightly forward at the end of the sentence to indicate the question type.