cognoscere

[pmda]

Orberg in Exercitia Latina XXI habet:

Estne facile Marcum cognoscere?

Resondeo: Difficile Marcum cognoscere est.

et

Marcus difficile cognoscitur est.

Is the 'est' strictly necessary - especially in response 2. ??

[adrianus]

Respondeo: Difficile Marcum cognoscere est...Is the 'est' strictly necessary...

Here the "est" verb is accurate but strictly not necessary because it can be understood.
"Est" verbum hîc strictim necesse non est quod constatum at utile tamen.

Marcus difficile cognoscitur est.

Is the 'est' strictly necessary - especially in response 2. ??

Here "est" is wrong because there's already a verb.
Hîc "est" verbum perperam scribitur quod iam exstat verbum.

[furrykef]

strictly not necessary

Don't you mean "not strictly necessary"? Your wording sounds like "strictly unnecessary" to me...

It's also worth pointing out here that any usage of "est" is not strictly necessary (unless its omission would cause unacceptable ambiguity), though it's omitted most often in things like proverbs and inscriptions, not typical speech.

Here "est" is wrong because there's already a verb.[/i]

More precisely: because there's already a finite verb. "Cognōscere" is also a verb, just an infinitive one, so it can take "est".

[adrianus]

As you say, furrykef. That sounds good to me.
Ut dicis, furrykef. Id benè sonat, ut mihi videtur.