Roger Woodham replies:Worth and worthwhile

There is no difference in meaning between the first two sentences. In both of them we are talking about the value of an activity. The difference is one of form only and both forms are frequently used

Is it worth repairing this car?

Worth usually follows the verb to be and is often used with a preparatory it. It can then be followed by an -ing clause:

Note that with this construction, it can be used to refer to an action mentioned in the previous sentence:

This car is not worth repairing

With this structure the object of the -ing clause is made the subject of the sentence and the preparatory it becomes superfluous:

Be worth a lot of money

Worth is also often followed by a noun phrase when we are discussing the monetary value of something or somebody and saying how much it or they are worth. With this construction the question forms how much and what are often used:

be worth a lot / a great deal /etc

With these expressions we are saying how good, useful or reliable something or someone is:

Note that to be worth your weight in gold and not worth the paper they are printed on are both idioms. Word order cannot be changed.

be worth somebody's while

If you say it will be worth your while to do something, it means that you will get some (financial) advantage or benefit from it, even though it may take some time or trouble:

Note from the above example that worth can also be modified by well to make the expression well worth.

worthwhile

If something is worthwhile it is well worth the time, money or effort that you spend on it:

Sometimes, worthwhile simply means of value and can be used in a similar way to worth with preliminary it. Compare the following:

worthless

Note that if something is worthless, it has no value or use: