Hi, Kris! Well, as far as I know, in English it's Thomas. But here in Brazil, for example, it would become Tomas (without "h") or Tomás. The writing changes and the pronunciation as well.

In the United States, the most common form of the name is "Thomas." The H isn't pronounced. The first syllable has the same vowel sound as rhymes with "Mom" or "bomb." The accent is on the first syllable. The "s" sound the end is soft, a pure hiss without any hint of a buzz. In the US, it is one of the ten most common men's first names. The nickname (short form) is "Tom." The diminutive is "Tommy."

In English, the name 'Thomas' is always spelt with an 'Th' at the beginning, but it's pronounced exactly like a 'T'. The 'h' is dropped for spelling the diminutive, Tom and Tommy. If I came across someone called 'Tomas' in Britain, I'd presume that he or his family originated from elsewhere. His family could have chosen the Irish spelling without the 'h', or they could be Spanish or Czech, for example.

Hi Kris, in Spanish, it is written: Tomás. Regards!