I know that "это звучит ужасно' means "that sounds terrible" but how do you say: "You sound German/Russian/American" et cetera in Russian?
People don't generally "sound" in Russian; using звучать here would suggest an absurd notion that the speaker themself is a sound. Ты говоришь как немец (male) / немка (female) is one way to say it, but it's ambiguous in that it can also be understood as "you say the kinds of things a German would say". You can rephrase it more directly as У тебя немецкий акцент (or немецкий выговор), but that doesn't quite have the tentativeness of "You sound German". What I would probably say in this situation is something like: А ты немец/немка? На слух похоже.
That may look like a surprising amount of complications but it reflects a cultural difference, in that accents are less of a thing in Russia than they are in the English-speaking world. Most Russians can only very vaguely tell one accent from another, not only foreign, but regional ones as well—which are, in themselves, if not less prominent in Russian then at least something that's less common for people to listen for. Also, as "accents" are a subject that comes with a lot of stereotyping that's only considered offensive when it's invoked on a personal level, "You sound X" is a thing people are more likely to politely shy away from saying—hence the lack of a streamlined expression.
In Russian a person can hardly sound like a national language speaker (but not like a person having any emotional state). So there are two different options:
- If you want to emphasise the non-living object of perception (e.g. the sound of speech), I suggest the same archaic participle forms ending in -но;
Как (будто) по-немецки сказано / сказал(а).
like (as if) by-German-MODUS.ADV. said-PAST.P.-NEUT.SG. / said--0-MASC.SG.PAST (FEM.SG.PAST)
1.2. The more simple structures would be:
1.2.1 Как (будто) немцем сказано.
like (as if) a German-MASC.SG.INSTR. said-NEUT.SG.
1.2.2. Как (будто) немкой сказано.
like (as if) a German-FEM.SG.INSTR. said-PAST.P.-NEUT.SG.
1.2.4. Как (будто) немец сказал.
like (as if) a German-MASC.SG.INSTR. said-0-MASC.SG.PAST
1.2.5. Как (будто) немка сказала.
like (as if) a German-FEM.SG.INSTR. said-FEM.SG.PAST
1.3. With the verb, you can also add some ты and это:
1.3.1. Ты это как будто немец (немка) сказал(а).
1.3.2. Ты как будто немец (немка) это сказал(а).
2) Alternatively, if you want to emphasise the verb, you could use the звучать with это:
Это звучит как будто / словно (сказано) по-немецки.
Basically, Это звучит goes well with any structure from 1.2.
So звучать and an address a person present at the moment of conversation don't go well together because звучать implies non-evidentiality, whilest ты is usually addressed to a visible person present at the moment of a communication.