Clubbing of income

Dear Sir, Situation - 1 If husband and wife both employed in the different pvt ltd company and both earn taxable income then if they want to clubbed their income then is it possible for clubbing as per law. Situation - 2 If husband has taxable income from salary head and his wife earn bank interest which is not taxable. In this situation can the assessee clubbed his wife's income into his income and file the return if they want. Please clarify this anyone.