Traditionally, actors wait in the wings of the theatre until it’s time for them to step on the stage. If we say someone or something is waiting in the wings, we mean that they are ready to make an entrance, be brought to public attention, or take over a role or a position: A new start-up wave is waiting in the wings. My deputy is waiting in the wings and will take over once I retire. To wait on someone hand and foot means to serve someone well, attending to all personal needs: I am going to wait on my mother hand and foot on Mother’s Day. This hotel is a perfect place for a getaway when you just want to relax and be waited on hand and foot.

Something that is practical is useful or effective: The book is practical and easy to read, not some theoretical fluff. Practicable is more narrowly defined. It means feasible, possible: It is simply not practicable to complete the project by the end of this month. Consider the following sentence: I don’t think your suggestion is very practical/practicable. If you mean to say the suggestion is ineffective, choose practical here; if you want to say it is impossible, choose practicable. A practical joke is a mischievous trick intended to embarrass someone and involves a physical action rather than words: Peter played a practical joke on his roommate by slipping a whoopee cushion onto his chair.

Assume and presume both mean “to take for granted or to suppose that something is true”. Although they are often used interchangeably in this sense, there is a slight difference in the degree of confidence held by the speaker or writer. When you assume something, you are not really sure. When you presume something, you are making an educated guess based on probability. If your cat is limping, you might assume that it had had an accident. However, if you had seen an event take place—say, a fall or a fight, you might presume that this was the primary cause of the limp.

Continuously and continually are words with similar but not quite identical meaning. Continuously describes an action that goes on and on without interruption: Jogging continuously for 30 minutes or more is best for burning calories. Continually, on the other hand, describes things that occur repeatedly or regularly with intervals of interruption: As information is continually being updated, it is important to keep on top of the latest developments. The same distinction holds true for the adjectives continuous and continual. The most common mistake is to use continuous when you actually mean continual. For example: The continuous rumble of thunder during the night kept me awake. A continuous ten-second clap of thunder is terrifying enough, whereas non-stop, continuous thunder for the whole night would be apocalyptic! The word continual would fit better in this context.