Answered by Shaykh Ilyas Patel
Is it considered an oath if you think of the oath in your head and say “WAllahi” out loud?”
In the name of Allah, the inspirer of truth
If you just said the oaths in your mind like you said ( so I would think of it, then say Wa Allah, so that then I would have to that thing) and not uttered them verbally, then this does not count as an oath, but it is just mere intention, but if you uttered the oaths verbally then for each oath which you have broken you have to give a kaffarah from the following things as mention in Quduri:
Expiation of a broken oath
1. The expiation of an oath is:
Freeing a slave. There suffices for it that which suffices in [the expiation of zihar]. [Or] If one wishes, he may clothe ten destitute people, [giving] each of them one garment or more, the minimum of [each] being that in which salah is valid, [or] If one wishes, he may feed ten destitute people, like the feeding in the expiation of zihar.
2. If one is not capable of any of these three things, one fasts three consecutive days
Swearing and oath is effected by use of the swearing letters. The swearing letters are:
The waw, such as one’s saying, “Wallahi” [By Allah]
The ba, such as one’s saying, “Billahi” [By Allah]
The ta, such as one’s saying, “Tallahi” [By Allah]
And Allah alone knows best
The scholars mention that an oath pronounced in other than Arabic has the same details and legal implications.
Please go to www.SunniPath.com and search for fiqh of oaths for details.
And Allah knows best