Do I use a capital I when using it in the middle of sentence with an apostrophe?

For example should the follow sentence be?

That's what i'd say.


That's what I'd say.

In English, the word 'I" should always be capitalized, no matter where it appears.

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clive you are not using a capital I In It
The WORD "I." The personal pronoun "I" is always capitalized. Not the letter!

I accept this, but nobody accepts this when I tell them. Even my husband who is better in English than me doesn't accept.
But I would like to know the reason for "I" being capitalized and why are other pronouns not capitalized in the middle of the sentence like "I"?

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Hi Jay;

That's what I'd say.

Here is some historical information from http://www.etymonline.com/index.php?term=I&allowed_in_frame=0

12c. shortening of O.E. ic, first person singular nominative pronoun, from P.Gmc. *ekan (cf. O.Fris. ik, O.N. ek, Norw. eg, Dan. jeg, O.H.G. ih, Ger. ich, Goth. ik), from PIE *eg-, nominative form of the first person singular pronoun (cf. Skt. aham, Hitt. uk, L. ego (source of Fr. Je), Gk. ego, Rus. ja, Lith. aš). Reduced to i by mid-12c. in northern England, it began to be capitalized mid-13c. to mark it as a distinct word and avoid misreading in handwritten manuscripts.

The reason for writing I is ... the orthographic habit in the middle ages of using a 'long i' (that is, j or I) whenever the letter was isolated or formed the last letter of a group; the numeral 'one' was written j or I (and three iij, etc.), just as much as the pronoun. [Otto Jespersen, "Growth and Structure of the English Language," p.233]

Quote from: The Approach to Philosophy, by Ralph Barton Perry
In all my living, he argues, whether I sin or turn to God, whether I doubt or believe, whether I know or am ignorant, in all I know that I am I.

If "He" is capitalized in the middle of a sentence, it refers to God.

Quote from Quiet Talks on Power, by S.D. Gordon

Ah, my friend, I verily believe you are the very one the Master had in mind, for He had John put into his gospel a living illustration of this ideal of His that goes down to the very edge of human unlikeliness and inability.
But in His absence the work He has begun is to be entrusted to their hands.