Conditional Sentences & Question Tags — Complete Guide for BCS

Concept

This topic covers two highly tested BCS grammar areas: Conditional Sentences (if-clauses) and Question Tags (tag questions). Both follow strict structural patterns, making them predictable — and scoreable — once you master the rules.

Conditional sentences express a condition and its result. There are four main types (Zero through Third), plus mixed conditionals. BCS frequently tests whether you can match the correct tense combination.

Question tags are short questions added to the end of a statement to seek confirmation. BCS loves testing special/irregular tag patterns.

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Key Rules

Part A: Conditional Sentences

The Four Types:

Type	Meaning	If-clause Tense	Main Clause	Example
Zero	General fact/truth	Present Simple	Present Simple	If you heat water, it boils.
First	Real / possible future	Present Simple	will + V1	If it rains, I will stay home.
Second	Unreal present / hypothetical	Past Simple	would + V1	If I were rich, I would help you.
Third	Unreal past / regret	Past Perfect	would have + V3	If I had studied, I would have passed.
Mixed	Past condition → present result	Past Perfect	would + V1	If I had taken the medicine, I would be well now.

Critical BCS Rules:

1. "If I WERE" — Always "were", never "was":

   • "If I were a bird, I would fly." (Subjunctive mood)
   • "If he were here, he would help us."
   • This applies to ALL subjects in 2nd conditional: I were, he were, she were, it were.
   • BCS often gives "If I was" as a trap option — always reject it.

2. "Unless" = "If...not":

   • "Unless you study, you will fail" = "If you do not study, you will fail"
   • NEVER use "not" with "unless": "Unless you don't study" is DOUBLE NEGATIVE and wrong.

3. "Wish" follows conditional logic:

   • Present wish (unreal now): "I wish I were rich" (Past Simple / were)
   • Past wish (regret): "I wish I had studied harder" (Past Perfect)
   • Future wish: "I wish he would come" (would + V1)

4. "As if / As though":

   • Present unreal: "He talks as if he knew everything" (Past Simple)
   • Past unreal: "He talked as if he had seen a ghost" (Past Perfect)

5. "It's time / It's high time" + Past Simple:

   • "It's time you went home." (NOT go — use past form for unreal urgency)
   • "It's high time we changed our strategy."

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Part B: Question Tags

Basic Rule: Positive statement → Negative tag. Negative statement → Positive tag.

• "You are coming, aren't you?"
• "He didn't go, did he?"

Formation: Use the auxiliary/modal from the statement. If no auxiliary, use do/does/did.

• "She likes tea, doesn't she?" (no auxiliary → does)
• "They have finished, haven't they?" (auxiliary: have)

Special Cases (BCS Favorites)

These irregular tags appear in almost every BCS exam:

Statement	Tag	Why
I am late	aren't I?	Exception! (NOT "amn't I")
Let us go	shall we?	"Let us" → shall we (suggestion)
Let him go	will you?	"Let + 3rd person" → will you
Open the door (imperative)	will you?	All imperatives → will you
Don't make noise	will you?	Negative imperative → will you
Everybody knows this	don't they?	Everybody/everyone = plural in tag
Nobody came	did they?	Nobody = negative → positive tag
Nothing happened	did it?	Nothing = negative → positive tag
Somebody called	didn't they?	Somebody = plural in tag
He rarely comes	does he?	Rarely = negative → positive tag
She hardly knows him	does she?	Hardly = negative → positive tag
He never goes there	does he?	Never = negative → positive tag
He seldom eats out	does he?	Seldom = negative → positive tag
There is a book on the table	isn't there?	"There" stays as subject in tag
One should do one's duty	shouldn't one?	"One" stays as "one" in tag
He used to play cricket	didn't he?	"used to" → didn't (or usedn't)
He need not go	need he?	"need" as modal → need
He dare not speak	dare he?	"dare" as modal → dare
I am not wrong	am I?	Negative of "am" → am I

The Negative-Meaning Words Rule: Words like rarely, hardly, scarcely, barely, seldom, never, few, little carry negative meaning. So the sentence is treated as negative → the tag must be positive.

• "He hardly works, does he?" (positive tag because "hardly" = negative)

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BCS Shortcuts

1. "If + Past" = 2nd conditional. If you see past tense after "if" and the situation is hypothetical/unreal, it is 2nd conditional. The main clause uses "would".
2. "If + Past Perfect" = 3rd conditional. Regret about the past. Main clause: "would have + V3".
3. "If I were" — ALWAYS. Never "If I was" in BCS. This is the #1 conditional trap.
4. Negative-meaning words → positive tag: rarely, hardly, scarcely, barely, seldom, never, few, little. Memorize this list.
5. "I am" → "aren't I?" This exception appears in almost every BCS tag question set.
6. Everybody/Nobody/Nothing tags: Everybody → don't they? Nobody → did they? Nothing → did it?

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Solved Examples (5 BCS-style MCQ)

Q1. If I ___ a king, I would help the poor.

• (a) am (b) was (c) were (d) had been
• Answer: (c) were
• Explanation: This is a 2nd conditional (unreal present). The if-clause uses Past Simple with the subjunctive "were" for all subjects. "If I were" is the only correct form — never "was" in this context.

Q2. If he had worked hard, he ___ passed.

• (a) will have (b) would (c) would have (d) had
• Answer: (c) would have
• Explanation: "If + Past Perfect" = 3rd conditional (unreal past). The main clause structure is: would have + V3. "Would have passed" expresses that the passing did not happen because the condition was not met.

Q3. He rarely visits us, ___?

• (a) doesn't he (b) does he (c) is he (d) isn't he
• Answer: (b) does he
• Explanation: "Rarely" carries a negative meaning, so the statement is treated as negative. A negative statement takes a positive tag. No auxiliary in the statement + present tense → "does he?"

Q4. I am your friend, ___?

• (a) am not I (b) amn't I (c) aren't I (d) isn't I
• Answer: (c) aren't I
• Explanation: "I am" is a special case. The standard tag is "aren't I?" (not "amn't I" which does not exist in standard English, and not "am not I" which is archaic). This is a BCS classic.

Q5. Nobody called me, ___?

• (a) didn't they (b) did they (c) did he (d) called they
• Answer: (b) did they
• Explanation: "Nobody" is a negative word, so the statement is negative. Negative statement → positive tag. "Nobody" is replaced by "they" in the tag (indefinite pronoun convention). Past tense (called) → "did they?"

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Common Mistakes — Watch Out!

1. "If I was" is WRONG in conditionals. Always use "If I were" for hypothetical/unreal situations. This is the subjunctive mood and applies to all subjects.
2. "Unless you don't study" is WRONG. "Unless" already means "if not". Adding "don't" creates a double negative. Just "Unless you study" is correct.
3. "Rarely/hardly/never" = negative. Students often give a negative tag after these words, creating a double negative. "He rarely comes, doesn't he?" is WRONG. The correct tag is "does he?" (positive).
4. "Everybody" is singular in grammar but plural in tags. "Everybody knows this, don't they?" (not "doesn't he").
5. Mixed conditional confusion: The 3rd conditional is about the past. If the question is about an unreal present situation, use 2nd conditional. Do not mix them unless the sentence specifically links a past condition to a present result.

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Question Pattern Recognition

Pattern 1 — "Fill in the if-clause": Look at the main clause. "would + V1" → if-clause needs Past Simple (2nd conditional). "would have + V3" → if-clause needs Past Perfect (3rd conditional). "will + V1" → if-clause needs Present Simple (1st conditional).

Pattern 2 — "Fill in the main clause": Look at the if-clause. "If + Present Simple" → main clause: will + V1 (1st). "If + Past Simple/were" → main clause: would + V1 (2nd). "If + Past Perfect" → main clause: would have + V3 (3rd).

Pattern 3 — "Add the question tag": Step 1: Is the statement positive or negative? (Watch for hidden negatives: rarely, hardly, never, nobody, nothing). Step 2: Use the opposite polarity for the tag. Step 3: Use the same auxiliary/modal from the statement.

Pattern 4 — "I am" tag: If you see "I am" in the statement, the answer is almost certainly "aren't I?"

Pattern 5 — Imperative/Let tags: "Let us" → shall we? All other imperatives (including "Let him/her/them") → will you?