The word 'clever' is an adjective, a word that describes a noun as quick to understand, learn, and devise or apply ideas; skillful, smart. He had a clever solution to the problem. Any more clever ideas? A clever student will use a dictionary.
The word plan is both a noun (plan, plans) and a verb (plan, plans, planning, planned); for example: noun: 'That is a clever plan.' verb: 'I need to plan my escape.' The noun form for the verb to plan are planner and the gerund, planning.