Hello. See is a non-progressive verb in the english language. This means it does not take an -ing to express present continous tense (to express things happening right now). So, it only occurs in its present tense form (see/ sees). The only exception to that, is when you use the verb (see) as in (meet) ex: I am seeing someone today = I am meeting someone today. I hope this clarifies it all.
The verb "to see" is not commonly used in the continuous tense in English. See here: https://www.learnenglish.de/grammar/verbstative.html
Duo rejects when i write we are seeing
That is correct.
In US/UK English, "see" is a stative verb; it is not used in the -ing form in its basic meaning "perceive with one's eyes". Similarly with "have" and "understand" and "love" and several similar verbs.
- "I see your daughter." (I see your daughter with my eyes. Basic meaning: no -ing possible.)
- "I am seeing your daughter." (I regularly go out on dates with your daughter. Metaphorical meaning: -ing possible.)
- "I have two dogs." (I own two dogs. Basic meaning: no -ing possible.)
- "I am having two dogs." (I am eating two dogs. Metaphorical meaning: -ing possible.)
- "I understand." (I comprehend what was said. Basic meaning; no -ing possible on the verb.)
- "I am understanding." (I am the sort of person who has compassion. This uses the adjective "understanding".)
Ham hamari kitaben dekhte hain (regularly) and Ham hamari kitaben dekh rahe hain (right now) would both be "We see our books" in English and Wir sehen unsere Bücher in German.
then there is difference in we see and we are seeing in german
Yes, because "we see" and "we are seeing" mean quite different things in US English, which is what Duolingo uses to teach.
- I see your daughter. = Ich sehe deine Tochter.
- I am seeing your daughter. = Ich gehe mit deiner Tochter aus.
There are some times when we use "am seeing"-- for example, "I can't believe what I am seeing" or "I'm seeing it, but I don't believe it" or "Am I seeing what I think I'm seeing?"
So I guess we use the 'am' when you need to affirm that you are indeed seeing the thing that has already been mentioned, or something like that.
not allowing present continuous instead of present simple
Are you from India, perhaps? Or a non-native speaker of English?
At least in US English (which Duolingo uses to teach German), we don't use "see" in the continuous forms when we're talking about observing something with our eyes.
So--there's nothing in German that limits meaning of sehen to stative verb ? Just a question of most frequent translation into English? Please confirm!
By the way, to this native speaker's ear,"I'm seeing my books" is perfectly grammatical. (e.g., JIM: "I left a candy bar on your bookshelf. Better check." ME: "I'm seeing my books, but I'm not seeing your candy." There's a kind of playfulness in this word choice, whereas "I see my books" is flavorless, fine, always a safe bet.