Help the detective finish her dramatic case notes.
"The prime suspect ___ an alien masquerading as a high school physics teacher."
The correct answer is is.
"The prime suspect" is a third-person singular noun (he/she/it), so it takes the singular verb "is".
Be
- ✅ I am tired. / She is tired. / They are tired. — present
- ✅ I was tired. / They were tired. — past
- ✅ She is running. — auxiliary for progressive
- ✅ It was broken. — auxiliary for passive
Be has 8 forms (am/is/are/was/were/be/being/been) — the most irregular verb in English. Two jobs: copula linking subject to complement (She is a doctor) and auxiliary for progressive and passive.
Trap: be changes for person AND number in both present and past. No other English verb does this. Learn the grid: I am / you are / he is / we are + I was / you were / he was / we were.
Present tense
- I work here. — simple present (habit/permanent)
- I am working now. — present progressive (happening right now)
- I have lived here for 10 years. — present perfect (started past, still true)
- I have been waiting for an hour. — present perfect progressive (duration up to now)
Four present tense forms: simple (habits/facts), progressive (now/temporary), perfect (past → present relevance), perfect progressive (ongoing duration). Each encodes a different relationship between the action and the present moment.
Trap: "I am living here for 10 years" ❌ — started in the past + still true = present PERFECT (have lived/have been living), not progressive.
Subject
- ✅ The list of items is wrong. — subject = list (singular), not items
- ❌ The list of items are wrong. — trapped by nearest noun
- ✅ Running is good exercise. — gerund as subject
- ✅ What he said surprised me. — clause as subject
The subject is the noun/pronoun/phrase before the verb that controls its number and person. Finding the true subject — especially through prepositional phrases — is the key to subject-verb agreement.
Rule: strip away prepositional phrases between subject and verb. Whatever's left is the true subject. The list (of items) is wrong.
A1 | Elementary | Beginners
- ✅ My name is Anna. — present simple of be
- ✅ Where is the station? — basic *wh-*question
- ✅ I have two brothers. — possession with have
- ✅ She likes coffee. — third-person -s
These are A1 sentences — the starting level of the CEFR framework. At A1 you can introduce yourself, ask and answer simple personal questions, and handle basic everyday transactions using present tense, be/have/do, and core vocabulary.
If you can say these but freeze at normal speaking speed, you're solidly A1 — and that's exactly where to start.
Easy
- She is a teacher. — one verb form, one rule
- I have two cats. — basic possession, short sentence
- He doesn't like coffee. — simple negation with do-support
- Only one answer is clearly correct; distractors are obviously wrong.
Easy marks beginner-level challenges: A1–early A2, one rule at a time, everyday vocabulary, no trick questions.
Use "Easy" when you want to build confidence on a specific rule without interference from other grammar or tricky contexts.