the length of time

[atabitaraf]

I have read it in the grammar book, Digest by Trudy Aronson, that the length of time is required to be used in the perfect continuous tenses. My question is, 'Is it correct to use lately or recently instead of the length of the time?'

For example: I have been watching TV recently.

 

[5jj]

Yes.

 

[5jj]

The length of time is often not stated with the present perfect:

Have you heard from your sister?
I've worked in eight countries altogether.
George has just arrived.

 

[emsr2d2]

I have read it in the grammar book no comma here Digest by Trudy Aronson no comma here that the a length of time is required to be used in is expressed using the perfect continuous tenses. My question is no comma here 'Is it correct to use "lately" or "recently" instead of the length of the time?'

Note my corrections above. You correctly italicised the title of the book but you incorrectly italicised "by Trudy Aronson".

 

[Skrej]

that the length of time is required to be used in the perfect continuous tenses.

The length of time is often not stated with the present perfect:

I think the OP is asking about the perfect continuous tenses, although your answer still applies to that, too.

Edit: Some examples.
Tom was tired because he had been jogging.
Tom has been feeling blue (lately). (note the optional use of 'lately')
Tom will be tired because he will have been exercising so hard.

 

[Tdol]

Be careful of grammar books that lay down the law so absolutely.