Each language, whether signed or spoken, has its conjunctions. ASL has some conjunctions, such as finish (very common), then, also or sometimes and, but, and so on.
Most rhetorical question terms (e.g. "how", "why", "when") with raised eyebrows are also conjunctions in ASL. Similarly, you can find a conjunction "when" in English. And, "because" is another conjunction in English.
Now the preschooler Juli had used ASL conjunctions that connect two phrases or simple sentences. For example, a few weeks ago Juli signed: eat then #tv.
Lately, Juli had used the ASL conjunction then several times. For example, one morning this week, Juli had a plan and talked about the future tense: (ix-me) eat yogurt finish then father come-here.
In this sentence, Juli clearly used a conjunction. Either of the ASL words finish and/or then in this sentence and context can function as a conjunction (possibly a double conjunction), but it's for ASL linguists to determine.
Juli has used and as in phrase, but not in conjunction. For example, ix-me want apple and ipad.
There are two different words for the concept of "why" in English: "because" (as a conjunction) and "why" (in a question). However, in ASL, the sign for the English words "because" and "why" is the same but has different intotation for a sentence type.
That is, the ASL sign why-conj (an equivalent to English as because is accompanied with the raised eyebrows, whereas why-q in a question is accompanied with burrowed eyebrows.
At this stage, three-year-old Juli didn't use facial intonation to indicate a question or a conjunction in a statement. However, she used why-conj in sentences. (see video)
In the next weeks (from age 3;2), Juli was seen using "because" or why-conj. For example, at age 3;3, Juli suddenly told me as I was sitting down for our dinner. She signed, ix rabbit cried! ("The rabbit was crying.") I asked, "Why?" She explained, because hurt.
Another, Juli and I got off our car on the grocery's parking lot, we saw a firefighter crew having a car wash fundraising event on the lot. Juli looked for a moment and uttered in ASL ix-det firefighter wash car rh-why car dirty.
Juli had used why-conj (or "because") from time to time. However, I hadn't seen Juli using this ASL sign in a question. However, I had seen Juli using "who?" though seldomly.
At 3;7, she continued to use this conjunction. E.g. ix-me need more water ix(in) pitcher why(because) water run-out.
This documentation project follows a baby's language acquisition, literacy development, and phonological acquisition in sign language, specifically ASL, week by week from gazing at birth to manual babbling, to first words just before the first birthday in a natural native-ASL environment and visual culture.
The second-year documentation continues to follow the same one-year-old child's language and phonological acquisition and literacy development in ASL on a weekly basis from the one-word stage to two-word and multiple utterances.
The third year documentation continues to follow the same child's ASL language and literacy development on a regular basis from age two to three. It surveys ASL phonological acquisition and more complex utterances.
The fourth year documentation continues to follow the same child's ASL language and literacy development on a regular basis from age three to four. It surveys ASL phonological acquisition and more complex utterances.
This five-year documentation and project follows the bilingual child's natural language acquisition in sign language from newborn to age five.