Even though English and German belong to the same language family (the Germanic family), it turns out that knowing a language such as Spanish (or French, Italian, Portuguese, or anything of the Romance language) is an advantage in the advanced stages of learning English.
How come? Certainly, knowing German helps with all the basic vocabulary and the grammar. Knowing Haus is useful to learn house, knowing Wasser does no harm when learning water, and so on. Some German prepositions (bei, in, durch,...) and pronouns (ich, sie,...) also resemble their English counterparts. This basic stuff can be mastered quickly if you already know German. However, when it comes to reading real texts, basic stuff is not and won't ever be enough. You need words for abstract things, qualities, procedures... there is no quick method here but to learn the vocabulary little by little.
Surprisingly, for a Spanish speaker, much of this vocabulary acquisition is for free: he or she only has to get used to slightly different spellings of words he or she already knows, while a German speaker may have a harder time deciphering a English text.
You don't believe this can be true? Look at this table:
|difference||diferencia||Unterschied; Meinungsverschiedenheit; Differenz|
|transform||transformar||verwandeln; umformen, umwandeln|
|insist||insistir||bestehen, beharren, großen Wert legen|
|paint||pintar||malen, bemalen; anstreichen; lackieren; schminken; bildlich schildern, beschreiben|
|sincere||sincero||offen, ehrlich, aufrichtig|
|area||area||Gebiet, Bereich; Teil; Raum; (Grund-, Boden)Fläche; Vorplatz|
|impression||impresión||Prägung, Abdruck, Eindruck, Ahnung, Nachdruck|
|immediate||inmediato||unmittelbar, unvermittelt, direkt; nächste(r, s); umgehend, prompt|
Note, first of all, that the word on the Spanish column isn't necessarily the exact translation of the English word, but it is the word the Spanish speaker immediately thinks of when seeing the English word. Most of the times, the meaning of the Spanish word is identical or very similar to the English word; it is possible to read English resorting constantly to these cognates. Of course there are false friends, but that isn't as terrible as it is for a German who has never studied Latin to relate the German words on the third column to the English words.
Anyway, I must confess that I came across a lot of words which look alike in all three languages, i.e. a German could make use of a cognate to understand a English word. A few examples:
However, such cognates don't seem enough to allow the German to rely heavily on cognates when reading English. This article contains words such as useful, basic, language, column, advanced, constantly, etc. all which exist in Spanish (in Spanish versions, of course), and most of which have no cognate in German.
Finally, let me make clear that I'm only guessing. I'm can't say for sure that Germans really have a hard time when reading English. After all, they speak such excellent English, and they even complain because of the influence of English on German.