回头 vs 等（一）会儿（近义词）

1)回头 is an adverb(There is also a phrase made of the verb 回 and object 头 meaning"to turn one's head)".等(一)会儿 is a phrase.
2)Both 回头 and 等(一)会儿 mean"a moment later"and function as an adverbial:
3)In examples①②and③the two expressions are interchangeable.
4)等(一)会儿 can be separated by inserting a word,e.g.等了（一）会儿.回头is an adverb and cannot be separated,but it may be confused with the phrase formed by the verb 回 and object 头.e.g:
5)In example④等了（一）会儿 is not the adverbial,but the predicate;while in example⑤回头 is not an adverb,but a phrase made of the verb 回 and the object头.