"I am walking quickly."

[spdl79]

Would είμαι περπατάω γρήγορα also be correct?

[D_..]

Nope! There is only one present tense in Greek, so there is no need to add the verb to be - είμαι to express any tense properties. Περπατώ (or περπατάω) will suffice.

[spdl79]

Thanks D! So, περπατώ γρήγορα would presumably completely suffice as well?

[D_..]

Yes!