Aviation radio calls are built so a scratchy two-second transmission still has one meaning. Registration numbers are spoken one character at a time, with niner, tree, and fife for 9, 3, and 5. A standard call names the facility first, then who you are, where you are, and what you intend. After the first contact, ATC may shorten a civil call sign to the last three characters, and that short form is the same aircraft.
Registration numbers, one character at a time
Civil aircraft use the registration, the N-number, on the radio. Letters use the phonetic alphabet. Digits are spoken one at a time, and three of them have aviation pronunciations so they do not collapse into another word on a noisy frequency: 9 is niner, 3 is tree, and 5 is fife (AIM 4-2-8).
N935TF is therefore "November Niner Tree Fife Tango Foxtrot." Grouping the digits into "nine thirty-five" is ordinary speech and the wrong phraseology. Saying "niner three five" gets the 9 right and then drops the special pronunciations for 3 and 5. The keyed form uses all three: niner, tree, and fife, then the phonetic letters.
You will mostly decode this rather than transmit it. Part 107 does not require you to carry a radio. When you monitor a tower or a CTAF, the call sign is how you tell one airplane from another. "Cherokee" plus a registration is a type and an N-number, not two aircraft.
The four-part call, facility first
The standard order is who you are calling, who you are, where you are, and what you intend (AIM 4-2-3). The facility or the traffic call comes first. That is the reverse of a phone call, which is why the exam can scramble the same words into three plausible sentences.
The transmission that follows the order is: "Lakeview Tower, Cherokee Four One Six Papa Golf, ten miles west, inbound for landing." Lakeview Tower is who is being called. Cherokee Four One Six Papa Golf is who is speaking. Ten miles west is where. Inbound for landing is the intent.
Leading with the request ("Inbound for landing, Lakeview Tower...") puts the intent in the slot that belongs to the facility. Leading with the aircraft ("Cherokee Four One Six Papa Golf, Lakeview Tower...") puts the caller ahead of the station being called. Same facts, wrong order. When you listen, grab the first words as the place the call is addressed to, then the call sign, then the position, then the plan.
The shortened call sign is the same airplane
On initial contact you hear the full registration: "November Eight Four One Quebec Kilo." A minute later the controller says, "One Quebec Kilo, extend downwind." That is the same aircraft. After communications are established, ATC may abbreviate a civil call sign to the last three characters. N841QK becomes "One Quebec Kilo."
The short form is not a phraseology error the pilot must have corrected, and the aircraft did not change its call sign because it switched from ground to tower. Two different-sounding call signs on the same frequency can be one airplane. If you are building a mental picture of the pattern, count aircraft by the last three characters once ATC has shortened them, not by whether the word "November" is still attached.
Section 107.73 lists radio communication procedures as a knowledge area on the initial test and on recurrent training. The point for a remote pilot is situational awareness around airports: who is talking, where they say they are, and what they are about to do. Times in those broadcasts are Zulu. The Zulu time page covers the clock and how a runway number is spoken.
A pattern call you can parse
You are holding at 200 feet AGL on a job near a towered airport, listening only. The frequency produces: "Lakeview Tower, Cherokee Four One Six Papa Golf, ten miles west, inbound for landing." You mark one Cherokee, ten miles west, coming in to land. The tower answers with a runway and a pattern entry. Later the same voice is addressed as a shortened call sign using the last three characters of that registration. You do not add a second airplane to the count. You keep the first one on downwind and you keep the drone clear until that traffic is no longer a factor. Nothing in the radio exchange is a clearance for the unmanned aircraft.
If you do self-announce on a CTAF, the same skeleton applies: name the traffic you are calling, say that you are a drone, give position and altitude in feet AGL, and state what you are doing. The phraseology questions in this set are about the manned call you must be able to read.
The traps
The N-number trap is grouping and everyday pronunciation. "Nine thirty-five" collapses two digits. "Three" and "five" are intelligible in a quiet room and are still the wrong aviation words. Niner, tree, and fife are the pronunciations the question keys.
The order trap reuses one correct sentence and moves the pieces. Facility, aircraft, position, intent. If the first words are the request or the call sign, the order has already failed.
The abbreviation trap treats "One Quebec Kilo" as a second aircraft, a controller mistake, or a new call sign for a frequency change. It is the same civil aircraft, shortened after the first contact to the last three characters.
Drill the word order on the free practice test. The airport module in the course puts the same calls next to the frequencies you will actually monitor.