Some grammar stuff.

REDUCED ADJECTIVE CLAUSES
Debemos de asegurarnos que sea el mismo sujeto el que haga la accion.
Adjective conector/subject + be verb se omiten.
Adjective conector/subject with no be verb , el verb se convierte a - ING

The woman who is waving to us is the tour guide = The woman waving to us is the tour guide.
The letter which was written last week arrived today = The letter written last week arrived today.
The pitcher that is on the table is full of iced tea. = The pitcher on the table is full of iced tea.
I don't understand the article that appears in today's papers. = I don't understand the article appearing in today's papers.



DOES NOT REDUCE
Son 2 sujetos diferentes que hacen la accion.

The woman that I just met is the tour guide.
The letter which you sent me arrived yesterday.

REDUCED ADVERB CLAUSES
Debemos de asegurarnos que sea el mismo sujeto el que haga la accion.

Subject y be verb se omiten.
Subject y no be verb se omite el subject y el be verb se convierte a - ING

Although he is rather unwell, the speaker will take part in the seminar. = Although rather unwell, the speaker will take part in the seminar.

When you are ready, you can begin your speech = When ready, you can begin your speech.

Although he feels rather sick, the speaker will take part in the seminar. = Although feeling rather sick, the speaker will take part in the seminar.

When you give your speech, you should speak loudly and distinctly. = When giving your speech, you should speak loudly and distinctly.