Subjunctive Mood

Moods is the way to express the attitude of the speaker to what is being said. Subjunctive means subordinate or dependent. A subjunctive mood expresses something that is not fact like possibilities, doubts, wishes, desires, suggestions, or conditions.We use subjunctive when we
• want something to happen,
• imagine something happening, or
• anticipate that something will happen.

[1] EXPRESSING DESIRE/SUGGESTION

There are two common forms of subjunctive used to express desire or suggestion.

VERB + THAT + SUBJECT + VERB

The common verbs used in this structure are: ask, command, demand, insist, propose, recommend, require, suggest, urge, warn, etc. For examples,

• The teacher suggested that she study harder.
• The doctor recommended that he not eat salty food.
• My mom insists that I get up early.
• We urged that he deliver the raw materials on time.

Note: We also use "should + infinitive" instead of subjunctive.

ADJECTIVE + THAT + SUBJECT + VERB

These adjectives are: critical, important, essential, necessary, vital, etc. For examples,

• It is important that you study hard.
• It is vital that students not cheat during exams.
• It is essential that she be on time.
• It is necessary that he wear helmet.

[2] EXPRESSING POSSIBILITIES

Subjunctive mood is used to make prediction/assumption; for examples,

• It may rain tomorrow.
• We will go on holiday.
• All of these problems could happen.
• It's going to be a tough job.

Subjunctive mood is used to express conditions; for examples,

• If you heat the water to 100 degree, it boils.
• If you don't breath, you die.
• If you park here, the police will fine you.
• If I have money, I will lend you some.

[3] EXPRESSING A CONTRARY TO THE FACT

Subjunctive mood is used to express the contrary to the present with the following structures.

- If + past simple
- Wish /if only+ past simple
- As if / as though + past simple

For examples,
• If I were rich, I would buy that school.
• I wish I were able to finish my work on time.
• He speaks as if he were my boss.
• I doubt if you would go with us.

Subjunctive mood is used to express the contrary past with the following structures.

- If + past perfect simple
- Wish/if only + past perfect simple
- As if/as though + past perfect simple

• If I had studied hard, I would not have failed my test.
• Had he been more careful, the accident would not have happened.
• I wish I had not spoken such stupid words.
• He behaved as if he had not done anything wrong.