Conditional Sentence

As is typical for many languages, full conditional sentences in English consist of a condition clause or protasis specifying a condition or hypothesis, and a consequence clause or apodosis specifying what follows from that condition. The condition clause is a dependent clause, most commonly headed by the conjunction if, while the consequence is contained in the main clause of the sentence. Either clause may appear first.

Different types of conditional sentences (depending largely on whether they refer to a past, present or future time frame) require the use of particular verb forms (tenses and moods) to express the condition and the consequence. In English language teaching the most common patterns are referred to as first conditional, second conditional and third conditional; there is also a zero conditional and mixed conditional.

Subject–auxiliary Inversion

Subject–auxiliary inversion involves placing the subject after a finite auxiliary verb, rather than before it as is the case in typical declarative sentences (the canonical word order of English being subject–verb–object).

Note that forms of the verb be are included regardless of whether or not they function as auxiliaries in the sense of governing another verb form.

A typical example of subject–auxiliary inversion is given below.

• Sam has read the paper. - Statement
• Has Sam read the paper? - Yes–no question formed using inversion

Here the subject is Sam, and the verb has is an auxiliary. In the question, these two elements change places (invert). If the sentence does not have an auxiliary verb, this type of simple inversion is not possible. Instead, an auxiliary must be introduced into the sentence in order to allow inversion:

• Sam enjoys the paper. - Statement with the non-auxiliary verb enjoys
• *Enjoys Sam the paper? - This is idiomatically incorrect; simple inversion with this type of verb is considered archaic
• Does Sam enjoy the paper? - The sentence formulated with the auxiliary does now allows inversion. For details of the use of do, did and does for this and similar purposes.

For exceptions to the principle that the inverted verb must be an auxiliary, see below.

It is also possible for the subject to invert with a negative contraction (can't, isn't, etc.). For example:

• He isn't nice.
• Isn't he nice? - The subject he inverts with the negated auxiliary contraction isn't.

Compare this with the uncontracted form Is he not nice? and the archaic Is not he nice?.

Subject–verb Inversion in English

Subject–verb inversion in English is a type of inversion where the subject and verb (or chain of verbs, verb catena) switch their canonical order of appearance, so that the subject follows the verb(s), e.. A lamp stood beside the bed → Beside the bed stood a lamp. Subject–verb inversion is distinct from subject–auxiliary inversion because the verb involved is not an auxiliary verb.

C1 | Advanced

C1 is the fifth of six levels in the Common European Framework of Reference for Languages (CEFR), sitting between B2 (Upper-Intermediate) and C2 (Proficiency). It's classified as Advanced — the stage where you stop translating in your head and start thinking in English.

What a C1 user can do

At this level, you're expected to handle complex, demanding language across a wide range of situations:

• Reading — You can understand long, complex texts, including specialized articles and technical instructions outside your own field. You pick up on implicit meaning, not just what's stated directly.
• Speaking — You express yourself fluently and spontaneously with minimal searching for words. You use language flexibly for social, academic, and professional purposes.
• Writing — You produce clear, well-structured, detailed text on complex subjects, with controlled use of organizational patterns, connectors, and cohesive devices.
• Listening — You follow extended speech even when it isn't clearly structured or when relationships between ideas are only implied.

What C1 grammar looks like

C1-level grammar goes well beyond accuracy with tenses and articles. You're expected to use advanced structures naturally, including:

• Inversion for emphasis (Rarely have I seen such dedication.)
• Mixed and advanced conditionals (Had she known, she would never have agreed.)
• Subjunctive forms in formal contexts (It's essential that he be informed.)
• Cleft sentences for focus (What concerns me is the timeline.)
• Complex noun phrases and nominalization (The government's repeated failure to act…)

The difference between B2 and C1 isn't just knowing these structures exist — it's using them appropriately and with control across different registers.

Self-check: If you can read an opinion piece in The Guardian or The Economist and follow the argument without a dictionary, and if you can write a structured response disagreeing with it, you're likely operating at C1.

How C1 fits in the CEFR scale

The CEFR has six levels: A1 → A2 → B1 → B2 → C1 → C2. C1 is where most universities and professional bodies set their language requirements for non-native speakers.

Ready to test yourself? Try Pass the Test to Determine Your English CEFR Level or go straight to the C1/C2-level test. You can also practice key C1 structures like Inversion and Conditional Subjunctive.

Difficulty: Hard

Hard difficulty. Difficulty levels represent author's opinion about how hard a question or challenge is.