12) English verbs in contexts (contextually dependent and required verb forms))

**Conditional sentences**

Sentences consisting of exactly two parts: a main clause and an if-clause (also called a conditional clause), where special rules dictate that "will" and the conditional mood "would" strictly cannot be used in the if-clause.

**If-clause (conditional clause)**

A dependent clause introduced strictly by the conjunction "if", where the future "will" must be substituted by other tenses capable of expressing future time.

**The meaning of "if" (real conditionals)**

A meaning translating to "jestliže/pokud", consisting of usage in zero and first conditionals where the condition can potentially be fulfilled.

**The meaning of "if" (unreal conditionals)**

A meaning translating to "kdyby", consisting of usage in second and third conditionals to indicate that we are talking about a reality that is different from the real one because conditions were not, are not, and will not be fulfilled.

**The meaning of "if" (whether)**

A meaning translating to "zda" in object clauses, where it is highly recommended to replace it with "whether" to avoid misunderstanding, because unlike in conditional clauses, future "will" or the conditional mood can actually be used after it.

**Unreal conditionals**

Conditional sentences consisting of a main clause with the conditional mood to indicate that the described event did not happen in reality.

**Substitution of future "will"**

A grammatical necessity in time and conditional clauses consisting of completely replacing "will" with present simple, present perfect simple, or present perfect continuous tenses.

**Present simple in conditional/time clauses**

A tense substitution consisting of replacing "will" for grammatical reasons to express future time in the first conditional and in time dependent clauses.

**Present perfect simple in conditional/time clauses**

A tense substitution consisting of replacing the structure "will have done" with "have done", used to express that one event will be completely finished by a certain moment in the future, strictly earlier than the activity in the main clause.

**Present perfect continuous in conditional/time clauses**

A tense substitution consisting of replacing the structure "will have been doing" with "have been doing", used to express that one event will be in progress until a certain moment in the future.

**Reported speech**

A grammatical structure consisting mostly of interpreted commands and questions.

**Indirect (reported) questions**

A complex syntactic structure consisting of exactly two parts: an introductory clause and the indirect question itself, which has the exact structure of a statement and never uses inversion.

**Introductory clause**

The first part of an indirect question consisting of a statement, question, or command, which exactly dictates what punctuation mark will be placed at the very end of the whole sentence.

**Introductory expression**

The connecting part of an indirect question consisting of "if/whether" for yes/no questions, or "wh- expressions" and "how" for wh- questions.

**If/whether (in reported questions)**

Introductory expressions consisting of interpreting yes/no questions, where "whether" is much better because "will" can be used after it without confusing it with the conditional "if".

**Wh- expressions and "how"**

Introductory expressions consisting of the exact words used to interpret and introduce wh- questions.

**Rules and changes in reported speech**

A set of specific grammatical changes consisting of changes in deictic expressions, syntactic changes, and tense changes called back-shift.

**Deictic expressions**

Expressions (such as adverbials of time and place, personal, possessive, and reflexive pronouns) consisting of reflecting the same reality but having completely different forms (e.g., "today" changes to "that day", "here" changes to "there") depending on the exact situation, time, and place from which the question is interpreted.

**Syntactic change in reported speech**

A structural change consisting of changing interrogative sentences (questions) into declarative sentences (statements) by completely removing inversion, and simultaneously changing imperatives into infinitives or modal verbs.

**Indirect commands**

A syntactic structure used to interpret commands, consisting of replacing the original imperative completely with infinitives (e.g., "not to come") or modal verbs (e.g., "mustn't come").

**Inversion**

A syntactic feature consisting of an operator being placed directly before the subject, which is completely missing in indirect questions and subject questions because they follow the structure of a standard statement.

**Back-shift (changes in tenses)**

A grammatical rule in reported speech consisting of shifting the tense one step back, which happens exclusively if the introductory clause is limited to the past time, meaning the described activity is over and not relevant anymore.

**Future in the past**

A specific tense shift consisting of changing the operator "will" to "would", used to express that a certain activity in the past was originally supposed to happen in the future, but that future moment has already passed and is now in the past as well.