剛生小高一，英文問題。

sing along, sing out, sing up 是 phrasal verbs,
Sing in 不是 phrasal verb.

(1) Armstrong also sang in many hit songs.
這句子 sang 是 intransitive verb (不及物動詞), 是無 object.
in many hit songs 是 prepositional phrase It functions as an adverbial phrase, modifying the main verb, “sang”.

其他的例子,
He sang in many languages.
He sang in the choir.
He always sang in the shower when he was young.

The underlined phrases are prepositional phrases.

(2) Armstrong also sang many hit songs.
這句子 sang 是 transitive verb(及物動詞), object 是 many hit songs

第一句子與第二句子分別在哪裡?
除了 sang 是 intransitive verb和 transitive verb外,
meaning 基本相同, 但分別細微

Armstrong also sang many hit songs.
Armstrong 並且唱許多的流行歌曲

Armstrong also sang in many hit songs.
Armstrong 並且在許多的流行歌曲唱過
(意味其他的歌手唱過)

Armstrong 是否指 Louis Armstrong?
在電影 movie “Hello Dolly”, Barbra Streisand 和 Louis Armstrong 各別唱,
Barbra Streisand 唱多, “Hello, Dolly!” 是首流行曲
用這句 Armstrong also sang in many hit songs.比較適當

純個人意見

題外:
Louis Armstrong 1967 年錄音, 獨唱流行曲 “What a Wonderful World”
其的歌手無法模仿.

1. sing in 的確少見，但你可以理解為 Armstrong在很多流行歌曲中都有份獻唱。

2. popularity 是否虛物不重要，重點是單數，或uncountable noun，那動詞就要加s。