a certain age for marriage

Another of my assessment sentences contains the word <marriage>. I had always thought the word is so frequent that even German speakers of English having been taught the lingo in a German secondary school for 7 - 9 years should know how to pronounce it. Alas ...

Let's look at <-iage> and <-age> (with any preceding letter but <i>).

<-iage> has three pronunciations:

1. /ɪdʒ/ as in marriage, carriage;
2. /iɪdʒ/ as in foliage, verbiage;
3. /iːɑːʒ/ as in triage (with /traɪɑːʒ, traɪɪdʒ, triːɪdʒ/ as variants.

<-age> also has three pronunciations:

1. /ɪdʒ/ as in appendage, average, cleavage, cottage;
2. /eɪdʒ/ as in  age, cage, page, rage, stage, wage;
3. /ɑːʒ/ as in camouflage, collage, espionage, curettage.

Which brings me to an important hint:
There's an excellent website with pronunciation tips which has recently been relaunched by John Maidment.

There's a lot more to be found there on the relations between spelling and pronunciation in English.