We do not give explicit information about the inflection and syntactic behaviour of idioms. Instead, we give the information implicitly, by showing in the explanations and examples which words inflect and which structure or structures are typically associated with an idiom. By using these as guidelines, learners will be able to produce their own sentences with idioms. For example, the following explanation If someone dots the i's and crosses the t's , they add the final minor details to a piece of work, plan, or arrangement. If you say that someone is skating on thin ice , you mean that they have got themselves into a difficult situation which may have serious or unpleasant consequences for them.
Explanations give other information about structures.
The explanation for the first meaning of marching orders begins If you are given your marching orders , you are made to leave something such as a job or a relationship. This is supported by the structures shown in the examples. Changes in syntax are sometimes shown in follow-on paragraphs. For example, at neck and neck , the main explanation In a race or contest, if two competitors are neck and neck , they are exactly level with each other, so that it is impossible to say who will win. Changes in syntax sometimes involve changes in spelling or form.