Parseltongue does not mark words for gender or number. Thus when speaking about someone else you cannot use 'she' or 'he.' Likewise, there is no 'they' or 'them' to note number. This has led to the use of the demonstrative pronouns. Rather than using such words, it has been simplified to 'that person' or 'this person,' or you can use the person's name reduced to the sounds available in Parseltongue.
Often gestures are used to clarify who is being spoken about. A snake may use their tail to point, or may flick their tongue in that direction. Humans typically just point or nod in the subject's general direction when speaking.
When referring to more than one of a subject, the number precedes the subject. But there is no plural form of a subject. Additionally, the demonstrative pronoun 'this' or 'that' is replaced by the number.
In the previous example, if we were talking about two or more cats we would simply state it as 'two cat black away run quickly.' it's often much easier to refer to someone by name. However, a lot of human names do not translate well to Parseltongue. Knowing how limited the sounds are, you can reduce a name to its Parseltongue equivalent.
Examples:
-The only letter in "Slytherin" not used in Parseltongue is the "y"; his name would normally be expressed as Slitherin as the "y" in "Slytherin" sounds like a short "i". (But be careful with the "th" sound; it is NOT pronounced like the "th" in the English word "slither"!)
-"Snape" can be expressed as written, but is pronounced more like "Ssna'peh" to most snakes. Most people who use "Snape" as a surname would go with Snep in Parseltongue, which sounds a bit closer to "Snape".
-My own first name, "Will", both begins and ends with forbidden sounds. Therefore, I need to convert the "W" at the beginning to a "V" and the "ll" at the end to an "sl" to produce the name Visl. ("Visl" is a nickname for the more formal Parseltongue name Visli'un).
-The most prominent class snake, who also serves as a Slytherin House pet, is usually known by the name "Basil". But that is an approximation for English speakers as the final sound does not exist in the language! Dropping the "i" gives his proper Parseltongue name: Basl. Likewise, his species name in Parseltongue is baslisik!
-The house elf known as "Dobby" would be expressed as Dabi using our conventions (because we only need to use the 'b' once). Note that Dabi in Parseltongue sounds exactly like "Dobby" in English!
-The first name of the Ravenclaw founder, Rowena, uses two vowel sounds next to each other, so we would use the ' symbol to separate out these sounds. Our conventions would have this written as Ro'ina, which - again - sounds exactly like "Rowena" in English.
Keep in mind that your goal is to approximate the way your name sounds - NOT the way that it is spelled. That said, your name is a personal choice - and who am I to question the way you wish to have it pronounced in another language?
One last point about converting your name to Parseltongue: some people whose name means something in English (or another language) can choose to translate that word into Parseltongue. For example: someone whose name is "White" could choose either to roughly translate the sounds of their name to something like Vaet or simply use the Parseltongue for "White", which is Ʃira. This word list will you help you out if you choose to translate part of your name this way.
Knowing the sounds, it's not too difficult to turn your name into its Parseltongue equivalent. Now recognizing it when a snake or Parselmouth hisses it? That's much harder!