Garlic is an ingredient whose impact you can fine tune, depending on how you handle it. A clove used unpeeled, peeled and left whole, crushed, sliced, chopped, minced, or turned into a paste, all yield slightly different results, and depend on the impact you are looking for. So, yes, a whole, peeled clove, cooked in some olive oil, for example, does impart flavor (as well as cooking the clove of garlic...which changes its flavor). It really depends on the desired impact of the garlic in your dish. In general, the more surface area, the stronger the flavor...but also the easier it is to burn and ruin the flavor of the whole dish.