These questions ask whether an outcome remains possible — now, in the future, or at a past moment — and whether a modal phrase has the right structure. Past items work the same way: could not reports a past inability or impossibility established by the evidence. The central decision is not how likely the event feels, but whether the context leaves it open or rules it out.
Decide whether the outcome is open
Read the evidence before looking at the modal. If the outcome is still open, may, might and could can all express positive possibility; do not rank these three by an imagined percentage. If the sentence presents non-occurrence as one possible outcome, choose may not or might not. If a measurement, physical limit or other conclusive fact makes an action impossible, choose could not. Once the meaning is settled, attach the bare verb directly to the modal. In a passive phrase, be is that bare verb, followed by the past participle.
| Meaning signal | Pattern to build |
|---|---|
| A positive present or future outcome remains open | may, might or could plus bare verb |
| Non-occurrence remains one open possibility | may not or might not plus bare verb |
| Known evidence rules the action out | could not plus bare verb |
| An open or impossible outcome is expressed in the passive | modal plus not when needed, then be plus past participle |
Use a two-pass check. First underline words showing uncertainty, feasibility or a firm limit and choose the meaning branch. Then inspect only the structure after the modal. May, might and could do not take to, an -s ending or an -ing form directly after them. The negative word comes immediately after the modal and does not change the form of the following verb.
Avoid these tempting forms
| Temptation | How to reject it |
|---|---|
| may, might or could followed by to | A core modal connects directly to the bare verb. Remove to before checking the sentence's meaning. |
| An -ing form or a third-person -s form directly after the modal | The modal already carries the finite work, so the next verb stays bare. A passive begins with bare be, not being. |
| could not when the context explicitly says the outcome remains possible | Could not presents inability or impossibility. An unresolved negative possibility needs may not or might not instead. |
| may not or might not when fixed dimensions make success impossible | Those forms leave room for success. A conclusive physical barrier calls for could not, followed by the bare verb. |
Try it
Which sentence contains a structural error in the may, might, and could possibility contrast?
- The pollen may to drift across the lake during the warm afternoon.
- A late frost might damage the shoots.
- The parcel could arrive tomorrow.
- The rehearsal may finish early.
Select all that apply. For the stated context, every outcome is still open. Which sentences correctly express the possibility that something will not happen?
- The licence could not to be issued this week, although every outcome remains open.
- The licence might not be issued this week.
- The northern peaches might not to ripen before the first market day.
- The northern peaches may not ripen before the first market day.
Complete with the negative phrase formed from could and the verb in brackets: Even at full extension, the ladder was two metres too short, so the technician ___ the skylight. (reach)