Ser + the present participle (el gerundio)
We had a discussion yesterday concerning the formation of the present continuous or present progressive tense in Spanish. Some confusion arose because choices between using estar or ser were thrown into the mix at the same time.
Somewhere along the line someone pointed out that the continuous tense is formed with estar + the present participle. (not ser).. Therefore, the 1°, sing. present progressive form would be estoy hablando (I think we used hablar as an exemplar). Past progressive would be estaba hablando, estuve hablando, conditional progressive, estaría hablando, future progressive estaré hablando, etc. to include the compound tenses.
So Ser was out of the picture. There was no soy, era, fui, sería, será hablando in the progressive tense.
However, I recalled having seen Ser used with the present participle many times. So I googled some fue+ present participle verbs to get some example sentences. Here are a few.
Fue hablando con un hermano de iglesia que me informó sobre esta cuestión, y me parece relevante.
Y a punto fijo no sé si el dolor que sentí fue escuchando la voz de la nena.
Muchas son las narraciones cortas que Rubén Darío, viajero consumado, fue escribiendo con el paso de los años aquí y allá (en Nicaragua, ...
Fue leyendo la Bitácora de las Indias Electrónicas lo que me abrió los ojos a nuevos marcos de análisis.
El recuerdo de la cárcel fue quedando atrás y cada vez fue hablando menos de ello en mi familia.
My question is: if these forms do not represent the past progressive, what exactly is the verb construction formed with Ser + the present participle.
I understand how Ser is used with the past participle (hablado, but I don't know exactly what construction Ser with the present participle is. It seems to be a verb tense and not Ser with another part of speech (gerund or adjective, adverb). What tense is it? Certainly that fue is not IR conjugated?
(Nice picture (avatar) that they they gave me. She looks better than me, I'm keeping it.)
Those "fue" are not from the verb "ser", but "ir":
Ir comiendo - Voy comiendo - Fui comiendo - Fue comiendo
Some of those constructions are simply the verb ir:
fue con su hermano a la iglesia hablando = fue hablando con su hermano a la iglesia
In other cases is a periphrasis, which is a special construction with two or more verbs, where one of them functions as an auxiliary verb, and loses part of its normal meaning. Spanish has over 100 of these constructions, and you cannot call them all "progressive", especially because only a small fraction of them are progressive. This periphrasis indicates that the second verb is gradually changing:
Voy mejorando = I am gradually/constantly improving
As you can see, in this last example, I am NOT going anywhere ("ir" losses part of its meaning)
You cannot say that "THE PROGRESSIVE" is formed with estar+gerundio, because Spanish has several progressive constructions, and each one is different from the rest. These double-verb constructions are called periphrases, and unfortunately, they don't have special names. Some of these periphrases:
andar + gerund
deber (de) + infinitive
echar a + infinitive
estar + gerund
estar + past participle
ir + gerund
ir + past participle
ir a + infinitive
ponerse a + infinitive
...and many more.
Certainly that fue is not IR conjugated?
Yes, it is, as Lazarus has explained. This construction is very useful to translate many verb-preposition idioms in English. For example, "Se fue corriendo" can be "He took off running" or "He ran off/away." And as Lazarus mentioned, other verbs can be used in the same way in place of ir: "Andaba llorando todo el tiempo" is "She was going around crying all the time."
However, ser is used to describe an innate quality of something or someone, and therefore doesn't fit into such constructions.
It appears that I stirred up a hornets nest with this question.
Stirring hornets is what we are here for!