Beginning: how change grammar of chosen lingq

Is it possible to change the grammar of a selected lingq? For instance: I have lingqed the word ‘houses’ , can I add the singular ‘house’ on the lingq?

That’s not possible, you can’t change a word form directly in a lesson. But you can always import words manually in any form you want on the Vocabulary tab. You’ll find the “import Vocabulary” button there.