Conditional usage: choose the correct verb form to complete He may not come, but we will get ready in case he ____.

Introduction / Context:
This question tests knowledge of verb forms in conditional like clauses with in case. The sentence is He may not come, but we will get ready in case he blank. We must insert a verb form that fits standard English and clearly conveys the idea that we prepare for the possibility that he comes, even though he might not.

Given Data / Assumptions:

The main clause uses the modal may to express uncertainty: He may not come.
The second clause begins with but we will get ready in case he blank.
In case usually introduces a clause that refers to a real possibility and typically uses a present tense form when referring to the future.

Concept / Approach:
In English, after in case when we are talking about a future possibility, we normally use the simple present, not will or another modal. For example, we say Take an umbrella in case it rains, not in case it will rain. In this sentence, the idea is similar: we will get ready now, in preparation for the possible event that he does come. Therefore, the correct choice is the present simple form does, corresponding to come, as in in case he does come. The verb come is understood and can be omitted after does in conversational English.

Step-by-Step Solution:
Step 1: Identify the structure in case he blank, which is a standard in case clause expressing a possible event. Step 2: Recall the rule that in case clauses about the future usually take present simple rather than will or may. Step 3: Recognise that the meaning is in case he does come, so the auxiliary should be does. Step 4: Substitute does into the sentence and read it as He may not come, but we will get ready in case he does. Step 5: Confirm that the sentence is natural and grammatically correct.

Verification / Alternative check:
We can compare similar examples: I will leave early in case there is traffic, We will keep the door open in case she arrives late. In each of these, the clause after in case uses present simple even though the meaning is future. Using will in those places would sound off to native speakers. Therefore, in the exam sentence too, does is the only option that both fits the rule and yields a natural sounding sentence.

Why Other Options Are Wrong:
Option A may repeats the modal from the first clause but creates an unnatural structure in case he may, which is not standard in English.
Option B will gives in case he will, which is incorrect because we avoid will in such subordinate clauses about future possibilities.
Option C shall is old fashioned and does not fit the grammar of subordinate clauses introduced by in case in modern usage.
Option E might also fails for the same reason as may; we do not say in case he might in this context.

Common Pitfalls:
A common error is to mirror the future meaning of the main clause by inserting will or another modal in the in case clause. However, English handles future meaning in subordinate clauses differently, often using the present tense. Remember patterns like in case it rains and if he comes rather than in case it will rain or if he will come. Practising with such patterns will make this type of question much easier to handle in exams.

Final Answer:
The sentence should read He may not come, but we will get ready in case he does.