Mapping
Deep analysis of student speaking and writing — every grammar phenomenon, vocabulary item, and pronunciation signal mapped to CEFR ground truth with full evidence trails.
Subject-verb agreement with plural subjects — plural nouns require plural verb forms
“fossil fuels is bad for the environment”Turn 2
Plural subject 'fossil fuels' requires 'are', not 'is'.
TO DESCRIBE EVENTS/HABITS/GENERAL TRUTHS — Affirmative form of lexical verbs to talk about repeated events or habits, and general facts
“it produce a lot of pollution”Turn 2
Third-person singular requires '-s' suffix: 'produce' → 'produces'.
Negative form of Present Simple — use of auxiliary DO/DOES + NOT for negation
“it not make pollution”Turn 6
Negation requires auxiliary 'doesn't' before the base verb.
Negative form of Present Simple — use of auxiliary DO/DOES + NOT for negation
“the wind don't blow every day”Turn 8
Third-person singular 'the wind' requires 'doesn't', not 'don't'.
TO DESCRIBE EVENTS/HABITS/GENERAL TRUTHS — Affirmative form of lexical verbs to talk about repeated events or habits, and general facts
“Solar energy come from the sun”Turn 10
Third-person singular 'Solar energy' requires 'comes'.
Passive voice — irregular past participle forms in passive constructions
“Solar panels can be builded on houses”Turn 10
'Build' has an irregular past participle 'built', not 'builded'.
Subject-verb agreement with plural subjects — plural nouns require plural verb forms
“Solar panels is expensive to buy”Turn 12
Plural subject 'Solar panels' requires 'are', not 'is'.
Subject-verb agreement — pronoun subject omission in subordinate clauses
“when is cloudy or nighttime”Turn 12
Missing subject pronoun 'it' in the subordinate clause.
WILL for future predictions — using "will" to make predictions about the future
“they will run out”Turn 4
Gerund after preposition — using the -ing form after prepositions like "without"
“without burning fuel”Turn 6
WILL for future predictions — using "will" + verb for future predictions
“technology will make solar panels cheaper and better”Turn 12
TO DESCRIBE EVENTS/HABITS/GENERAL TRUTHS — Affirmative form of lexical verbs to talk about repeated events or habits, and general facts
“renewable energy is really important for the future”Turn 14
Comparative adjectives — one-syllable adjectives use -er suffix, not "more" + adjective
“wind energy is more cleaner than fossil fuels”Turn 6
'Cleaner' is already comparative. Adding 'more' creates a double comparative.
Superlative adjectives — using "the most" + adjective for superlative forms
“The sun is the most powerful source”Turn 10
Comparative adjectives — using "better than" for irregular comparatives
“solar is better than wind”Turn 10
Comparative adjectives — using "more" + adjective for multi-syllable comparatives
“the sun is more reliable”Turn 10
BECAUSE clauses — linking a reason to a main clause using "because"
“renewable energy is important because... fossil fuels is bad for the environment”Turn 2
WHEN clauses — subordinate time clauses with "when"
“When we burn fossil fuels”Turn 2
CAN/CANNOT for ability and possibility
“the earth cannot make more”Turn 4
CAN/CANNOT for ability and possibility
“Wind turbines can produce electricity”Turn 6
Relative clauses with THAT — defining relative clauses using "that"
“energy that can come again”Turn 4
Relative clauses with THAT — defining relative clauses using "that"
“birds that fly near them”Turn 8
THERE IS / THERE ARE for existence — expressing existence or non-existence
“there is not enough energy”Turn 8
Coordination with AND — joining clauses or phrases with "and"
“the turbines are very big and some people think they are ugly”Turn 8
Coordination with AND — joining verb phrases with "and"
“We need to protect the environment and reduce pollution”Turn 14