If you want to be perfectly and unimpeachably correct, you will pronounce the word forte , meaning something that is one’s strong point, identically to the word fort , and reserve the FOR-tay pronunciation only for the musical term.
Most people don't know about this distinction and pronounce it FOR-tay for all senses, both the “strong point” sense as well as the musical term.
Most people will not notice or care if you do that.
In fact, if you say that some subject is or is not your “fort”, people will look at you quizzically and perhaps even ask “do you mean FOR-tay?”.
On the other hand, if you use the pronunciation “FOR-tay” those of us who know the difference may judge you to be ignorant.
In either case, you take a risk of some sort.
Bryan Garner came up with the name “skunked term” for words like this, in his 1998 Dictionary of Modern American Usage : When a word undergoes a marked change from one use to another … it’s likely to be the subject of dispute.
Some people (Group 1) insist on the traditional use; others (Group 2) embrace the new use.…
Any use of [the word] is likely to distract some readers.
The new use seems illiterate to Group 1; the old use seems odd to Group 2.
The word has become “skunked.”
My advice is to find a substitute word or phrase.
english.stackexchange.com/users/39/nohat
This source http://dictionary.reference.com/browse/forte suggests that the correct pronunciation of the word in your context is 'fort', as it is derived from the French 'fort' (strong) and the 'for-tay' pronunciation appeared through confusion with the 'forte' in music meaning loud, which is Italian and correctly pronounced 'for-tay'.
english.stackexchange.com/users/305/Brian Hooper
The Oxford Dictionary considers both forms to be correct.
The French feminine form was substituted for the masculine in English, similar to locale, morale etc.
The Pronunciation was latterly inflected.
english.stackexchange.com/users/145/Vaibhav Garg
As reported by the NOAD, the pronunciation is |ˈfɔrˌteɪ| or |fɔrt| , whenever forte means a thing at which someone excels, or loud/loudly.
In the first case, the origin of the word is from a French word fort (masculine), or forte (feminine), from Latin fortis ; in the second case the origin is the Italian word forte , from the Latin fortis .
The difference is that in the first case the word has been borrowed from French, while in the other case the word has been borrowed from Italian; in both the cases, the word derive from the same Latin word.
In Italian, the used word is forte for both the meanings; if there is any difference in the pronunciation is probably to differentiate the different origin of the English words.
english.stackexchange.com/users/252/kiamlaluno
Define "proper."
Language change, including pronunciation change is inevitable.
And reference books, no matter how prescriptive, cannot stem the tide of change, which can come from overwhelming use by the masses.
Frankly, I've never heard forte (meaning strength) pronounced as anything other than for-tay, and I am fifty two.
If you are unsure or waffling, I suggest you pronounce it the way that the social group you wish to identify with pronounces it, and that can include pronouncing it differently around different people.
english.stackexchange.com/users/78616/pazzo
In common American usage I have always heard "for-tay" because saying "fort" sounds like another word spelled f-o-r-t meaning a temporary dwelling.
english.stackexchange.com/users/914/Picturepocket
I always heard the ‘strength’ meaning came from fencing, where you try to parry with the inner half of the blade (the forte), because it's stronger than the outer half, the foible.
If so, it would come from Italian rather than French, so two syllables.
english.stackexchange.com/users/8019/Tim Lymington
NOAD has three pronunciations: |ˈfɔːteɪ| |ˈfɔːti| |fɔːt|(with
the first one only for the musical term).
english.stackexchange.com/users/3479/F'x
I've always heard people say something like "Pronunciation is not my [for-tay]" ... but I feel that I've heard that the correct pronunciation is "Confusing people is my [fort]" What is the proper way to pronounce this word?
Is "forte" pronounced "fort" or "for-tay"?
english.stackexchange.com
<pronunciation>
english.stackexchange.com/questions/1545
english.stackexchange.com/users/16/Daniel LeCheminant
There is no complete agreement regarding the correct pronunciation of the word "forte", although it seems that most people will pronounce it "FOR-tay" in all contexts. However, the Oxford Dictionary considers both forms to be correct. By far the most common form is "FOR-tay" but it is up to you which you prefer to use as there is no rule.
There is no complete agreement regarding the correct pronunciation of the word "forte", although it seems that most people will pronounce it "FOR-tay" in all contexts. However, the Oxford Dictionary considers both forms to be correct. The Oxford Dictionary considers both forms to be correct.   But, If you want to be perfectly and unimpeachably correct, you will pronounce the word   forte , meaning something that is one’s strong point, identically to the word  fort , and reserve the FOR-tay pronunciation only for the musical term.  
This is not pronounced as anything other than "for-tay",  because saying "fort" sounds like another word meaning a temporary dwelling. It is generally agreed that both forms of pronunciation are acceptable.
The correct pronounciation may be "fort" but by far the most common one is "FOR-tay". Both are correct - as the word comes from the Italian and from the French it can be spoken either way. There is no rule on this - you can pronounce it the way people in your social group pronounce it. In American usage "fort" has another meaning and so that pronounciation would be confusing. The term also exists in fencing - again from the Italian.
But, If you want to be perfectly and unimpeachably correct, you will pronounce the word   forte , meaning something that is one’s strong point, identically to the word  fort , and reserve the FOR-tay pronunciation only for the musical term.   The Oxford Dictionary considers both forms to be correct.   
It is generally agreed that both forms of pronunciation are acceptable.