I found some sources that said that I could use both constructions to mean "It seems like verb..."
Therefore, are the following sentences equal in meaning?
泳いでいるように見えました。
泳いでいて見えました。
Japanese Language Stack Exchange is a question and answer site for students, teachers, and linguists wanting to discuss the finer points of the Japanese language. It only takes a minute to sign up.
Sign up to join this communityI found some sources that said that I could use both constructions to mean "It seems like verb..."
Therefore, are the following sentences equal in meaning?
泳いでいるように見えました。
泳いでいて見えました。
泳いでいるように見えた is the only correct choice in your context. 泳いでいて見えた is grammatical but it would mean something like "I could see it (e.g., a shark) while I was swimming".
-て見える takes an instant-state change verb whose teiru-form ta-form has an adjective-like meaning. 違う is a typical example of this. However, it does not need -ている to express the continuation of state. You can directly use the te-form:
You cannot use this construction for ordinary action verbs whose teiru-form expresses the progressive action ("is ~-ing"). 泳いで見える, 歩いて見える and so on are ungrammatical.
And not all instant-state-change verbs can be used with -て見える:
I don't know the exact criteria, but I think it's probably best to use -て見える only for clearly apparent qualities of something.
As far as I can see, -ているように見える has no such restriction. You can safely say 泳いでいるように見える ("appears to be swimming"), 知っているように見える ("it appears that they know it") and so on.
Therefore, are the following sentences equal in meaning?
Yes, it works equally under certain context, in practice.
One of the many use cases would be, when looking at an optical illusion. Suppose there's a picture, and if you look at it from one angle, you see a man swimming, but when you look closely, it's not. Don't ask me what it looks like up close. Looking at this picture, a boy might say "it looked like it was swimming!" in the following way:
泳いでいるように見えました
泳いでるように見えました
泳いでいて見えました (this is your example)
泳いでて見えました
泳いで見えました
We can shorten "見えました" to "見えた" too.
It may be worth noting your example "3. 泳いでいて見えました" may cause a debate by those who haven't been exposed to this version. The more I look at the sentence, the "wrong"er it seems, but when I mutter them it makes sense. It may be wrong after all, but somehow it makes sense to me, and I'm guilty of using it.
I hope another answer or comment would explain the logic behind this.