Marjoram will enhance the flavour of many different dishes. It is the perfect herb for seasoning meat but also works well when added to a medley of roast vegetables, tomato sauces, stews, soups and casseroles.
Marjoram is one of those herbs where the dried form has a much more concentrated flavour when compared to that of the fresh form. This makes it quite different from those herbs that actually have a much milder flavour when dried. The tendency of the flavours to intensify means that you can add it early when cooking dishes that take time. It will continue to release flavour as the dish cooks.
Fresh oregano has a more pungent, less sweet flavour than marjoram. So when using oregano as a substitute, only use half the amount.
Fresh marjoram is less flavourful than the dried version, which means that it may lose its intensity if cooked extensively. Your best bet is to add it a few minutes before the dish is removed from the heat.