Past progressive tense and Progressive tense

Past progressive tense noun - A progressive tense used to describe on-going action in the past.

Progressive tense and past progressive tense are semantically related. In some cases you can use "Progressive tense" instead a noun phrase "Past progressive tense".

Progressive tense noun - A tense of verbs used in describing action that is on-going.

Past progressive tense and progressive tense are semantically related. Sometimes you can replace phrase "Past progressive tense" with "Progressive tense", this phrases are similar.