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Future perfect

Future perfect is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Future perfect rather than just read about it. In short: The future perfect is a verb form or construction used to describe an event that is expected or planned to happen before a time of reference in the future, such as will have finished in the English sentence "I will have finished by tomorrow." It is a grammatical combination of the future tense, or other marking of future time, and the perfect, a grammatical aspect that views an event as prior and completed. English…

Key takeaways

  • Future perfect belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Future perfect to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Future perfect from memory before moving on to harder problems.

Reference excerpt

The future perfect is a verb form or construction used to describe an event that is expected or planned to happen before a time of reference in the future, such as will have finished in the English sentence "I will have finished by tomorrow." It is a grammatical combination of the future tense, or other marking of future time, and the perfect, a grammatical aspect that views an event as prior and completed.

English In English, the future perfect construction consists of a future construction such as the auxiliary verb will (or shall) or the going-to future and the perfect infinitive of the main verb (which consists of the infinitive of the auxiliary verb have and the past participle of the main verb). This parallels the construction of the "normal" future verb forms combining the same first components with the plain infinitive (e.g. She will fall / She is going to fall). For example:

She will have fallen asleep by the time we get home. I shall have gone by then. Will you have finished when I get back? The auxiliary is commonly contracted to 'll in speech and often in writing, and the first part of the perfect infinitive is commonly contracted to 've in speech: see English auxiliaries and contractions. The negative form is made with will not or shall not; these have their own contractions won't and shan't. Some examples:

I'll have made the dinner by 6 PM. He won't have done (or will not have done) it by this evening. Won't you have finished by Thursday? (or Will you not have finished by Thursday?) Most commonly the future perfect is used with a time marker that indicates by when (i.e., prior to what point in time) the event is to occur, as in the previous examples. However, it is also possible for it to be accompanied by a marker of the retrospective time of occurrence, as in "I will have done it on the previous Tuesday". This is in contrast to the present perfect, which is not normally used with a marker of past time: one would not say "I have done it last Tuesday", since the inclusion of the past time marker last Tuesday would entail the use of the simple past rather than the present perfect. The English future perfect places the action relative only to the absolute future reference point, without specifying the location in time relative to the present. In most cases the action will be in the future relative to the present, but this is not necessarily the case: for example, "If it rains tomorrow, we will have worked in vain yesterday." The future perfect construction with will (like other constructions with that auxiliary) is sometimes used to refer to a confidently assumed present situation rather than a future situation, as in "He will have woken up by now." The time of perspective of the English future perfect can be shifted from the present to the past by replacing will with its past tense form would, thus effectively creating a "past of the future of the past" construction in which the indicated event or situation occurs before a time that occurs after the past time of perspective: In 1982, I knew that by 1986 I would have already gone to prison. This construction is identical to the English conditional perfect construction. An obsolete term found in old grammars for the English future perfect is the "second future tense." For more information, see the sections on the future perfect and future perfect progressive in the article on uses of English verb forms.

Spanish In Spanish, the future perfect is formed as this:

The future of haber is formed by the future stem habr + the endings -é, -ás, -á, -emos, -éis, -án. The past participle of a verb is formed by adding the endings -ado and -ido to ar and er/ir verbs, respectively. However, there are a few irregular participles such as these:

abrir: abierto cubrir: cubierto decir: dicho escribir: escrito freír: frito hacer: hecho morir: muerto poner: puesto ver: visto volver: vuelto Verbs within verbs also have the same participle, for example, predecir ("to predict') would be predicho; suponer ("to suppose") would be supuesto. Also, satisfacer ("to satisfy") is close to hacer ("to do") in that the past participle is satisfecho. To make the tense negative, no is simply added before the form of haber: yo no habré hablado. For use with reflexive verbs, the reflexive pronoun is before the form of haber: from bañarse ("to take a bath"), yo me habré bañado; negative: yo no me habré bañado.

Portuguese In Portuguese, the future perfect is formed like in to Spanish:

subject + future of ter or haver + past participle eu haverei falado ("I will have spoken") eu terei falado ("I will have spoken") The future of ter is formed by the future stem ter + the endings -ei, -ás, -á, -emos, -eis, -ão (the 2nd person plural form tereis is, however, archaic). The past participle of a verb is formed in turn by adding the endings -ado and -ido to the stems of -ar and -er/-ir verbs, respectively. However, there are a few irregular participles such as these:

abrir: aberto cobrir: coberto dizer: dito escrever: escrito fazer: feito ganhar: ganho gastar: gasto pagar: pago pôr: posto ver: visto vir: vindo Several verbs that are derived from the irregular verbs above form their past participle similarly like the past participle of predizer ("to predict') is predito; for supor ("to suppose"), it would be suposto, and satisfazer ("to satisfy"), which is derived from fazer ("to do"), has the past participle satisfeito. To make the sentence negative, não is simply added before the conjugated form of ter: eu não terei falado. When using the future perfect with oblique pronouns, European Portuguese and formal written Brazilian Portuguese use mesoclisis of the pronoun in the affirmative form and place the pronoun before the auxiliary verb in the negative form:

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with Future perfect

Start with the simplest possible case. Write down what Future perfect claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Future perfect before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Future perfect ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Future perfect

In research
Future perfect appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Future perfect in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Future perfect is common in secondary-school and first-year university syllabi. It links to neighbouring topics Grammatical tenses, so understanding it makes those chapters shorter.
In everyday life
Look for Future perfect outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Future perfect in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Future perfect means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Future perfect out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Future perfect in simple terms?

The future perfect is a verb form or construction used to describe an event that is expected or planned to happen before a time of reference in the future, such as will have finished in the English sentence "I will have finished by tomorrow." It is a grammatical combination of the future tense, or…

Why does Future perfect matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Future perfect?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Future perfect.

Tags

  • Grammatical tenses

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