There are 9 parts of speech or word classes in English language:
– nouns
– pronouns
– determiners
– verbs
– prepositions
– adjectives
– adverbs
– conjunctions
– interjections

In English, there are 3 types of sentence mood:
– indicative mood,
– imperative mood,
– subjunctive mood.

We use indicative mood to express statements or questions.
– I went to the store.
– I don’t know where he is.
– Are you going out tonight?

We use imperative mood to express instructions.
– Call me!
– Wash the dishes.
– Don’t tell anyone.

We use subjunctive mood to express hope, suggestions and imagined scenarios.
– I wish I were a princess.
– Her mom suggested that she get a job.
– If I were you, I would wear something else.

There are 4 patterns of subjunctive mood:
1. Subjunctive with wish, if only, as if, as though
2. Subjunctive with conditional sentences type 2
3. Subjunctive with verbs of suggestions
4. Subjunctive with adjectives of importance

Subjunctive with Wish

Subjunctive for present hopes.

Pattern:
Subject + wish + (that) + Subject + past simple

I wish that I were a bit taller.
The fact: I am not tall.
The wish occurs in the present, not in the past.
All subjects, including singular subjects (I,he,she,it), use ‘were.’

Subjunctive for past hopes.

Pattern:
Subject + wish + (that) + Subject + had + past participle

I wish (that) I hadn’t eaten so much yesterday.
The fact: I ate so much yesterday.

Subjunctive with As If, As Though

As if/as though for present context.

Pattern:
Subject + base form / -s form + as if / as though + Subject + past simple

Robby acts as though he were a king.
The fact: Robby is not a king.

As if/as though for past context.

Past:
Subject + past simple + as if / as though + Subject + had + past participle

She acted as if she had never seen me before.
The fact: She had seen me before.

Subjunctive with Conditional Type 2

We use conditional sentences type 2 to express imagined scenarios that are impossible to happen in present context.

Pattern:
if clause: If + Subject + Verb 2
main clause: Subject + would + Verb 1

If I were you, I would wear something else.
The fact: I cannot become you.
The imagined scenario of I becoming you is not possible to happen.
The imagined scenario is for present context, not for the past.

If you had a phone, you could call me every day.
The fact: You do not have a phone.
The imagined scenario is for present context, not for the past.

Subjunctive with Verbs of Suggestions

Verbs of suggestions:
advise
ask
request
demand
insist
prefer
propose
recommend
suggest
urge

Pattern:
Subject + verb of suggestion + that + Subject / Object + base form
Subject + verb of suggestion + that + Subject / Object + be

All singular subjects (he/she/it) use base form without ‘s’.

The teacher requires all students be present.
The teacher requires all students are present. (wrong)

Her mom suggested that she get a job.
Her mom suggested that she gets a job. (wrong)
Her mom suggested that she got a job. (wrong)

Subjunctive with Adjectives of Importance

Adjectives of importance:
It is best (that)
It is crucial/essential/important/vital (that)
It is desirable (that)
It is imperative (that)
It is recommended (that)
It is urgent (that)
It is necessary (that)

Pattern:
It is + adjective of importance + that + Subject / Object + base form
It is + adjective of importance + that + Subject / Object + be

It’s necessary that we be vigilant to avoid another disaster.
It’s necessary that we are vigilant to avoid another disaster.(wrong)

It is crucial that he call me as soon as he gets home.
It is crucial that he calls me as soon as he gets home. (wrong)