present continuous. Please help me to correct the sentences. Many thanks.

  1. The present continuous tense is used to express an activity that takes place carrying a temporary nature.

  2. “They can ride a bike” or “they can ride bikes.”

  3. “where is your sister being?” or “Where is your sister?”

The present continuous tense is used to express an activity that is taking place at present (now). For example:

  1. They are riding a bike.

  2. Where is your sister going?

Thanks very much. However, please help me to correct the formers that I really need.

Many thanks.

NOT A TEACHER

I am not sure what is the former you are talking about.
Anglophile has corrected all your sentences.
What am I missing here?

#2. I think both sentences are correct. But note:

HE can ride a bike. [color=red]correct
He can ride bikes. [color=red]incorrect

(since one cannot ride more than one bike at a time, logically. )

But, since THEY (more than one person) is used here, the other sentence is correct in this context.

#3. “where is your sister?” is correct. because being cannot be used in continuous form to state someone’s state of being somewhere.

like Anglophile wrote: “where is your sister going?” the verb “go” can be used in continuous form to state the subject’s action which is taking place at that time.

I hope you understand my explanation.

Teachers,
correct me if I am wrong at any point.

yes, I understand. Thanks very much for your help.