Poles from South West Poland speak in German dialect?

Southern west Poland - "Silesia" there is many german influences in dialect, right?

Some, especially in the Wrocław region, and also Opole I think.

Not at all, population exchange in Lower Silesia after WW2 was nearly 100%, some German influence does exist but in Upper Silesia.

Well, depends. When it comes to the language, Polish Silesian was more spoken in Upper Silesia, when German Silesian was more spoken in Lower Silesia.

Was.

Well, he asked about German influence in Silesia, that's both past and today to me.

There was no continuity since the population was almost completely exchanged. I can't find the numbers for Lower Silesia, but in 1949 there were 2769 so called "autochthons" in Wroclaw, i.e. Poles who lived in the city before WW2. 774 spoke almost no Polish, 966 reasonable and 1029 were fluent. And according to several contemporary reports they were outsiders in the new community. A German influenced dialect simply couldn't develop under these circumstances.

Thank you guys for answers.

Btw, someone told me that Poland had have a very large German input in the last thousand year. This country was a very rare inhabitated land what have soaked up many immigrant from the overpopulated West. Is it right?

Partially...