Language tip of the week: whether or if?

In this weekly post, we bring more useful content from the Macmillan Dictionary to English language learners. These tips are based on areas of English (e.g. spelling, grammar, collocation, synonyms, etc) which learners often find difficult. This week’s language tip is about the differences in use between whether and if.

Both whether and if can be used to introduce indirect questions of the type that expect a ‘yes/no’ answer: She asked if/whether I liked jazz.
Use whether, but not if, before an infinitive: She can’t decide whether to marry him.
Use whether, but not if, after a preposition: There are doubts about whether the system is safe.
Use whether, but not if, immediately before ‘or not’: The question is whether or not the government has the right to interfere.
Whether is generally preferred when ‘or’ appears later in the sentence, but you can also use if: It is not clear whether/if the information was stolen or deliberately leaked to the press.