algae v seaweed

MUSCOVITE(1) Are these two words 100% interchangeable?"Algae" is simply more formal than "seaweed"?

I always thought of seaweed as a large rope-like sea plant, while algae was a formless mass of microorganisms. According to my dictionary though, seaweed qualifies as a type of algae, which I didn't know. So, seaweed is a type of algae, but not all algae

(1) Definitely not. Your dictionary should have made it clear that seaweed (in its many varieties) is only one type of alga (singular) or algae (plural).

(2) Both pronunciations are acceptable and commonly heard. You can please yourself.

Rover

1. Regardless of the exact scientific classifications, in ordinary speech and writing the word "seaweed" would mean the bigger types of marine plants, like kelp and the shrub-like, brown marine growths that thrive along seashores and often wash up on shore after a storm. The word "algae" implies microscopic marine plants, like the stuff you scrape off aquarium glass.

2. The "g" in "al

Hi

Below is the link to the pronunciation of 'algae'.

http://dictionary.cambridge.org/dictionary/british/algae

Rover_KE(2) Both pronunciations are acceptable and commonly heard. You can please yourself.

I didn't know this, but Rover's right. I pronounce it as I posted earlier, "g" as in gym. It seems the British prefer the other form with a "g" as in go. I learn something new every day.

Thanks everybody for their most interesting comments on seaweed v alga.

It sounds like we can draw parallels between seaweed/alga and mushroom/fungus? meaning any seaweed can be (formally) refered to as an alga.... and similarly, any mushroom can be called a fungus (but not the other way round)?

In the US the word "alga" is not used in everyday speech and writing; it's algae only. Scientifically, seaweed is apparently a kind of algae, and mushrooms are apparently fungus, but this distinction is lost in ordinary speech and writing. Moreover, the word "fungus" has very negative connotations in English and is avoided in everyday speech and writing.

AnonymousIn the US the word "alga" is not used in everyday speech and writing; it's algae only. Scientifically, seaweed is apparently a kind of algae, and mushrooms are apparently fungus, but this distinction is lost in ordinary speech and writing. Moreover, the word "fungus" has very negative connotations in English and is avoided in everyday speech and writing.