This is not an English sentence, and why does the second verb take a subjunctive rather than an infinitive form?

Question

No creo que ________ todos los deberes para el lunes. I don't believe to have done all my homework by Monday.HINT: Conjugate the yo form of "hacer" in El Pretérito Perfecto Subjuntivo

Answer

Hola Allison
Sentences introduced by an opinion in "negative" are followed by the subjunctive. Have a look at this lesson that will clarify your doubt:
[competency id= "6184"]
The English typo has been corrected. 
Muchas gracias,
Inma

Answer

Thanks Inma, but I learned that if the same subject is in both clauses (No creo and hacer los deberes) it would trigger the infinitive in the second clause?

Answer

Hi Allison
That is correct in certain cases, for example:
"Yo quiero estudiar más" (same subject in both, infinitive) but 
"Yo quiero que (tú) estudies más" (different subjects, needs subjunctive)
Also with "hope":
"Yo espero ganar la lotería" (same subject in both, infinitive) but
"Yo espero que ganes la lotería" (different subjects, needs subjunctive)
Notice the absence of "que" in the sentences with the same subject.
In order to be able to use an infinitive with "Yo no creo que..." you need to get rid of "que". For example:
Yo no creo haber hecho todos los deberes para el lunes. (although this sounds a bit formal)
With "que", the only option would be:
Yo no creo que haya hecho todos los deberes para el lunes.
Saludos
Inma

Answer

OK thanks!
So "Yo no creo haber hecho todos los deberes" or "Yo creo haber hecho todos los deberes" are correct, albeit formal?

Answer

Hi Allison
Sorry about this big delay on replying to your last query. The notification didn't come through back in October. 
So, yes, this is an option too but it would sound very formal:
"Yo no creo haber hecho/terminado todos los deberes para el lunes."
Un saludo
Inma

Answer

I am confused when " preterito " is appended to most of the tenses. This practice is not widely used in Spain or Latin countries. Why not use the tenses which are commonly used. I know that the preterite is used for past tense so when preterito perfecto subjuntivo is mentioned I expect that the past subjunctive is meant NOT the perfect subjunctive! I wonder whether other participants experience the same problem.