Bhí mé a féachaint teilifís agus duirt an phearsa, as Gaeilge: "Bhí fhios agam é!" ("I knew it!" dar leis an fotheideal.)

Dhá ceisteanna agaibh:

1. Should it not be "Bhí fios agam" (i.e., fios should not be lenited?)

2. Is "bhí f(h)ios agam é" incorrect grammatically? It seems like that é doesn't belong there like that.

Ceisteanna maithe, mar is iondúil.

1. Ní deirtear Tá / bhí fios agam más "I know / knew" atá i gceist. Actually, you can say tá fios agam, but it means "I have occult knowledge." In the common "I know" expression, a fhios means "its knowledge / knowledge of it".

2. The also common expression Tá / bhí a fhios agam é is probably technically redunant or even *gasp* ungrammatical. But it is well entrenched in the spoken language and is recognized as such in FGB, mura bhfuil seachrán orm.

The correct form is "Bhí a fhios agam" (= I have its knowledge) hence the lenition. It's usually pronounced "Vees" and the elision of the "a fhio-") bit is reproduced in the written language as "Bhí/Tá 's agam"
As Dennis says, "Bhí a fhios agam é/sin" is very common

And often written "Bhí 'fhios agam" or (incorrectly)"Bhí fhios agam" too.

See, I never heard that "a," hence the mistake. I've seen it written how many times and still I missed it. Whoops!

Thanks.

Dennis, this is what I learnt at Coleraine university about the sentences with "a fhios":

Tá a fhios agam = I have its knowledge.

Tá a fhios agam é = It is of knowledge at me : here, "a" comes from "de" (actually: tá d’ fhios agam é).

That's why you can say "tá a fhios agam" + something, it's not redundant, just the "a" is not the same word in the 2 patterns...